Purifying device for nitric oxide gas

Abstract

The utility model relates to a purification device for nitric oxide gas. The purification device comprises an extraction tower, a desorption tower, an alkaline washing tower, a condenser, an ethanol absorption tower and an adsorption tower which are communicated in sequence, a feed port of the extraction tower is communicated with a crude product gas source pipeline, a discharge port of the extraction tower is communicated with a feed port pipeline of the desorption tower, a discharge port of the desorption tower is communicated with a feed port pipeline of the alkaline washing tower, a discharge port of the alkaline washing tower is communicated with a feed port pipeline of the condenser, and a discharge port of the condenser is communicated with a feed port pipeline of the ethanol absorption tower. A discharge port of the ethanol absorption tower is communicated with a feed port of the adsorption tower through a pipeline, and a discharge port of the adsorption tower is communicated with a product collection bottle through a pipeline. Through the extraction tower, the desorption tower, the alkaline washing tower, the condenser, the ethanol absorption tower and the adsorption tower which are arranged in sequence, the device can efficiently purify nitric oxide gas, and each treatment unit can remove specific impurities, so that the finally obtained nitric oxide gas is ensured to have high purity.

Description

Technical Field

[0001] The utility model relates to the field of gas purification, in particular to a nitric oxide gas purification device. Background Art

[0002] Nitric oxide is a permanent gas that is colorless, odorless, slightly soluble in water, and soluble in solvents such as ethanol and carbon disulfide. Its liquid or solid state appears blue at low temperatures. Nitric oxide has a wide range of applications in fine chemicals, environmental protection, healthcare, scientific research, and electronics, among other fields. For example, it is used in the preparation of nitric acid and in nitration processes in the chemical industry, as an emergency abort agent in the polyvinyl chloride industry, and as a propellant for space rockets and satellites. With the rapid development of the semiconductor industry in recent years, demand for nitric oxide has grown rapidly due to its use in the formation, oxidation, and chemical vapor deposition of silicon oxide films. Furthermore, purity requirements continue to increase, and the demand for high-purity (99.99%) nitric oxide gas has been in short supply.

[0003] Patent CN108163823A discloses a method for preparing 4N purity nitric oxide gas, comprising adding dilute sulfuric acid to a sodium nitrite solution to generate crude nitric oxide. The crude nitric oxide is then subjected to alkali washing, dehydration, and primary drying. The primary dried gas is then passed through modified molecular sieves C2 and C5 for deep drying, followed by adsorption treatment in a cryogenic adsorber to collect the 4N purity product. The modified molecular sieves C2 and C5 are modified by soaking the molecular sieves C2 and C5 in a 10% nitric acid solution, removing them after 24 hours, and activating and drying them at 300°C for 8 hours. Patent CN118651826A discloses a method for refining nitric oxide gas, comprising adding dilute sulfuric acid and a saturated sodium nitrite solution as reaction materials to a synthesis reactor to generate crude nitric oxide gas. The crude nitric oxide gas is then subjected to alkali washing and condensation to remove water, followed by a three-stage adsorption process under cryogenic conditions to obtain nitric oxide gas with a purity of no less than 99.99%.

[0004] In the above patent, during the preparation of nitric oxide, nitric oxide will undergo a disproportionation reaction, resulting in a decrease in the yield of nitric oxide. At the same time, multi-stage adsorption will also promote the disproportionation reaction of nitric oxide gas to produce nitrogen dioxide and nitrous oxide, affecting the purity and yield of the product.

[0005] Therefore, it is necessary to invent a simple, safe and efficient nitric oxide gas purification device to improve the purity and yield of nitric oxide gas. Utility Model Content

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

[0007] In order to achieve the purpose of this utility model, the specific technical solutions provided by this utility model are as follows:

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

[0009] An extraction tower feed port is provided in the middle of the extraction tower, and an extraction tower discharge port is provided at the bottom of the tower;

[0010] The middle position of the analytical tower is provided with an analytical tower feed port, and the top position is provided with an analytical tower discharge port;

[0011] The bottom of the alkali washing tower is provided with an alkali washing tower feed port, and the top of the alkali washing tower is provided with an alkali washing tower discharge port;

[0012] The condenser is provided with a condenser feed port at one end and a condenser discharge port at the other end;

[0013] The bottom of the ethanol absorption tower is provided with an ethanol absorption tower feed port, and the top of the ethanol absorption tower is provided with an ethanol absorption tower discharge port;

[0014] The adsorption tower is provided with an adsorption tower feed port at the bottom and an adsorption tower discharge port at the top;

[0015] The extraction tower feed port is connected to the crude gas source pipeline, the extraction tower discharge port is connected to the analytical tower feed port pipeline, the analytical tower discharge port is connected to the alkali washing tower feed port pipeline, the alkali washing tower discharge port is connected to the condenser feed port pipeline, the condenser discharge port is connected to the ethanol absorption tower feed port pipeline, the ethanol absorption tower discharge port is connected to the adsorption tower feed port pipeline, and the adsorption tower discharge port is connected to the product collection unit pipeline.

[0016] Preferably, the ratio of the diameter to the height of the extraction tower is 38:4800, and an extractant inlet is provided at the top of the extraction tower, the extractant inlet is connected to the extractant tank, and the amount of extractant added is 1 / 4 to 1 / 3 of the volume of the extraction tower.

[0017] Preferably, the diameter and height ratio of the analytical tower is 38:4800, a kettle heater is provided at the bottom of the analytical tower, an extractant outlet is also provided at the bottom of the analytical tower, and the extractant outlet of the analytical tower is connected to the extractant recovery tank.

[0018] Preferably, the ratio of the diameter to the height of the alkali washing tower is 1:30, the interior of the alkali washing tower is filled with sodium hydroxide solution, and the amount of sodium hydroxide solution added is 1 / 3 to 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, and the refrigerant inlet and the refrigerant outlet are respectively connected to the refrigerant storage tank.

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

[0021] Preferably, a first valve is provided on the connecting pipe between the crude gas source and the extraction tower, a second valve is provided on the connecting pipe between the extraction tower and the decomposition tower, a third valve is provided on the connecting pipe between the decomposition tower and the alkali washing tower, a fourth valve is provided on the connecting pipe between the alkali washing tower and the condenser, a fifth valve is provided on the connecting pipe between the condenser and the ethanol absorption tower, a sixth valve is provided on the connecting pipe between the ethanol absorption tower and the adsorption tower, and a seventh valve is provided on the connecting pipe between the adsorption tower and the product collection unit.

[0022] The nitric oxide gas purification device of the utility model has the following beneficial effects:

[0023] 1. Through the sequential arrangement of an extraction tower, a desorption tower, an alkaline washing tower, a condenser, an ethanol absorption tower and an adsorption tower, this device can achieve efficient purification of nitric oxide gas. Each processing unit removes specific impurities, thereby ensuring that the final nitric oxide gas has high purity.

[0024] 2. By recycling and reusing the extractant in the analytical tower, the extraction effect is ensured while reducing the waste of extractant and the loss of nitric oxide gas. The alkaline washing tower is filled with sodium hydroxide solution of appropriate concentration and volume, which can effectively remove acidic impurities such as nitrogen dioxide and carbon dioxide without causing waste of resources and environmental problems.

[0025] 3. The refrigerant circulating in the condenser can effectively cool the gas to a suitable temperature and remove moisture; the anhydrous ethanol filled in the ethanol absorption tower can selectively absorb the nitrous oxide impurity in the gas that is more difficult to remove; the 13X molecular sieve filled in the adsorption tower can further deeply remove nitrous oxide and moisture, ensuring that the final nitric oxide gas meets high purity requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a nitric oxide gas purification device according to the present invention;

[0027] Explanation of the markings in the figure: 1. Crude gas source; 2. Extraction tower; 3. Desorption tower; 4. Kettle heater; 5. Alkali washing tower; 6. Condenser; 7. Ethanol absorption tower; 8. Adsorption tower; 9. Product cylinder; 10. Refrigerant storage tank; 11. Extractant recovery tank; 12. Extractant tank. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the preferred embodiments.

[0029] Device embodiment

[0030] like Figure 1 FIG. 1 is a schematic diagram of a nitric oxide gas purification apparatus according to the present invention. This embodiment provides an apparatus for purifying nitric oxide gas, comprising an extraction tower 2, a desorption tower 3, an alkaline scrubber 5, a condenser 6, an ethanol absorption tower 7, and an adsorption tower 8, which are sequentially connected. By sequentially disposing the extraction tower 2, the desorption tower 3, the alkaline scrubber 5, the condenser 6, the ethanol absorption tower 7, and the adsorption tower 8, the apparatus is capable of efficiently purifying nitric oxide gas. Each processing unit removes specific impurities, thereby ensuring that the resulting nitric oxide gas is of high purity.

[0031] An extraction tower feed port is located in the middle of extraction tower 2, an extraction tower discharge port is located at the bottom of extraction tower 2, and an extractant inlet is located at the top of extraction tower 2. The diameter-to-height ratio of extraction tower 2 is 38:4800. The extractant inlet is connected to extractant tank 12, from which extractant is introduced into extraction tower 2. The amount of extractant added is 1 / 4 to 1 / 3 of the volume of extraction tower 2. The extraction tower feed port is connected to a crude gas source 1 pipeline, and the extraction tower discharge port is connected to desorption tower 3. Through the coordination reaction between the extractant ferrous ions and nitric oxide in extraction tower 2, efficient extraction of nitric oxide is achieved and the occurrence of disproportionation reactions is reduced.

[0032] The desorption tower 3 is provided with a desorption tower feed port in the middle and a desorption tower discharge port at the top. A kettle heater 4 is provided at the bottom of the desorption tower 3, and an extractant outlet is also provided at the bottom of the desorption tower 3. The diameter and height ratio of the desorption tower 3 is 38:4800. The extraction tower discharge port is connected to the desorption tower feed port pipeline, and the extractant outlet of the desorption tower 3 is connected to the extractant recovery tank 11. The desorption tower discharge port is connected to the alkaline washing tower 5. By recovering and reusing the extractant in the desorption tower 3, the waste of the extractant is reduced while ensuring the extraction effect.

[0033] The alkali washing tower 5 is provided with an alkali washing tower feed port at the bottom and an alkali washing tower discharge port at the top. The diameter and height ratio of the alkali washing tower 5 is 1:30. The alkali washing tower 5 is filled with a sodium hydroxide solution having a mass concentration of 5%. The amount of sodium hydroxide solution added is 1 / 3 to 2 / 3 of the volume of the alkali washing tower 5. The alkali washing tower discharge port is connected to a condenser 6. The alkali washing tower 5 is filled with a sodium hydroxide solution of an appropriate concentration and volume, which can effectively remove the acidic impurities nitrogen dioxide and carbon dioxide without causing resource waste and environmental problems.

[0034] The condenser 6 is provided with a condenser feed port at one end and a condenser discharge port at the other end. The discharge port of the alkali washing tower is connected to the condenser feed port through a pipeline. The condenser 6 is also provided with a refrigerant inlet and a refrigerant outlet, which are respectively connected to the refrigerant storage tank 10. The condenser discharge port is connected to the ethanol absorption tower 7. The refrigerant circulating in the condenser 6 can effectively cool the gas to a suitable temperature and remove moisture.

[0035] The ethanol absorption tower 7 is provided with an ethanol absorption tower feed port at its bottom and an ethanol absorption tower discharge port at its top. The diameter-to-height ratio of the ethanol absorption tower 7 is 1:30. The ethanol absorption tower 7 is filled with anhydrous ethanol, with the amount of anhydrous ethanol added being 1 / 3 to 2 / 3 of the volume of the ethanol absorption tower 7. The condenser discharge port is connected to the ethanol absorption tower feed port through a pipeline, and the ethanol absorption tower discharge port is connected to the adsorption tower 8. The anhydrous ethanol filled in the ethanol absorption tower 7 selectively absorbs the difficult-to-remove nitrous oxide impurity in the gas.

[0036] Adsorption tower 8 is provided with an adsorption tower feed port at its bottom and an adsorption tower discharge port at its top. The diameter-to-height ratio of adsorption tower 8 is 45:1000. Adsorption tower 8 is filled with 13X molecular sieve. The ethanol absorption tower discharge port is connected to the adsorption tower feed port through a pipe, which in turn is connected to a product collection bottle 9 through a pipe. The 13X molecular sieve further deeply removes nitrous oxide and moisture, ensuring that the resulting nitric oxide gas meets high purity requirements.

[0037] A first valve is provided on the connecting pipe between the crude gas source 1 and the extraction tower 2, a second valve is provided on the connecting pipe between the extraction tower 2 and the decomposition tower 3, a third valve is provided on the connecting pipe between the decomposition tower 3 and the alkali washing tower 5, a fourth valve is provided on the connecting pipe between the alkali washing tower 5 and the condenser 6, a fifth valve is provided on the connecting pipe between the condenser 6 and the ethanol absorption tower 7, a sixth valve is provided on the connecting pipe between the ethanol absorption tower 7 and the adsorption tower 8, and a seventh valve is provided on the connecting pipe between the adsorption tower 8 and the product collecting bottle 9.

[0038] The implementation principle of this embodiment is:

[0039] When the operator uses the above-mentioned device to purify nitric oxide gas, the crude nitric oxide gas is first introduced into the extraction tower 2, and the extractant is introduced at the same time. The extractant reacts with the nitric oxide to remove most of the impurities. The extracted phase is introduced into the decomposition tower 3, and the nitric oxide gas is re-decomposed by heating. The nitric oxide gas is then introduced into the alkali washing tower 5 to remove the acidic impurities nitrogen dioxide and carbon dioxide. After that, the gas is introduced into the condenser 6 to remove moisture. Finally, the gas is introduced into the ethanol absorption tower 7 and the adsorption tower 8. The anhydrous ethanol inside the ethanol absorption tower 7 can selectively absorb the nitrous oxide impurity that is more difficult to remove in the gas. The 13X molecular sieve in the adsorption tower 8 can further deeply remove nitrous oxide and moisture, and finally high-purity nitric oxide gas is obtained.

[0040] In order to achieve better purification effect, the specific steps are as follows:

[0041] The crude nitric oxide gas with a purity of 99% is introduced into the extraction tower 2 at a flow rate of 8 L / min. At the same time, the extractant is transported from the extractant inlet at the upper end of the extraction tower 2. The extractant is a 1 mol / L ferrous sulfate solution. The extract phase obtained after the extraction is passed into the decomposition tower 3 for temperature decomposition. During the decomposition, the temperature is raised to 110°C. At the same time, the decomposed extractant is discharged from the extractant outlet at the bottom of the decomposition tower 3 for extractant recovery.

[0042] The analyzed gas is passed into the alkali washing tower 5, which is filled with a sodium hydroxide solution with a mass concentration of 5%. After the gas is washed with alkali to remove nitrogen dioxide and carbon dioxide impurities, it is passed into the condenser 6 for condensation and water removal. The refrigerant in the condenser 6 is dichloromethane, and the refrigerant temperature is -30°C.

[0043] After passing through the condenser 6, the gas is passed into the ethanol absorption tower 7, where anhydrous ethanol absorbs the nitrous oxide impurity in the gas. The gas after ethanol absorption is passed into the adsorption tower 8 filled with 13X molecular sieve, where the nitrous oxide and water are further deeply removed with the 13X molecular sieve. The gas after adsorption is collected in the product collection bottle 9 to obtain a nitric oxide product with a purity of 99.991%.

[0044] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A nitric oxide gas purification device, characterized in that: It includes an extraction tower, a decomposition tower, an alkali washing tower, a condenser, an ethanol absorption tower and an adsorption tower which are connected in sequence; An extraction tower feed port is provided in the middle of the extraction tower, and an extraction tower discharge port is provided at the bottom of the tower; The middle position of the analytical tower is provided with an analytical tower feed port, and the top position is provided with an analytical tower discharge port; The bottom of the alkali washing tower is provided with an alkali washing tower feed port, and the top of the alkali washing tower is provided with an alkali washing tower discharge port; The condenser is provided with a condenser feed port at one end and a condenser discharge port at the other end; The bottom of the ethanol absorption tower is provided with an ethanol absorption tower feed port, and the top of the ethanol absorption tower is provided with an ethanol absorption tower discharge port; The adsorption tower is provided with an adsorption tower feed port at the bottom and an adsorption tower discharge port at the top. The extraction tower feed port is connected to the crude gas source pipeline, the extraction tower discharge port is connected to the analytical tower feed port pipeline, the analytical tower discharge port is connected to the alkali washing tower feed port pipeline, the alkali washing tower discharge port is connected to the condenser feed port pipeline, the condenser discharge port is connected to the ethanol absorption tower feed port pipeline, the ethanol absorption tower discharge port is connected to the adsorption tower feed port pipeline, and the adsorption tower discharge port is connected to the product collection unit pipeline.

2. A nitric oxide gas purification device according to claim 1, characterized in that: The ratio of the diameter to the height of the extraction tower is 38:4800. An extractant inlet is also provided at the top of the extraction tower. The extractant inlet is connected to the extractant tank. The amount of extractant added is 1 / 4 to 1 / 3 of the volume of the extraction tower.

3. The nitric oxide gas purification device according to claim 1, characterized in that: The diameter and height ratio of the analytical tower is 38:4800. A kettle heater is provided at the bottom of the analytical tower. An extractant outlet is also provided at the bottom of the analytical tower. The extractant outlet of the analytical tower is connected to an extractant recovery tank.

4. The nitric oxide gas purification device according to claim 1, characterized in that: The diameter and height ratio of the alkali washing tower is 1:

30. The interior of the alkali washing tower is filled with sodium hydroxide solution, and the amount of sodium hydroxide solution added is 1 / 3 to 2 / 3 of the volume of the alkali washing tower.

5. The nitric oxide gas purification device according to claim 1, characterized in that: The condenser is further provided with a refrigerant inlet and a refrigerant outlet, and the refrigerant inlet and the refrigerant outlet are respectively connected to the refrigerant storage tank.

6. The nitric oxide gas purification device according to claim 1, characterized in that: The diameter and height ratio of the ethanol absorption tower is 1:30, and the interior of the ethanol absorption tower is filled with anhydrous ethanol. The amount of anhydrous ethanol added is 1 / 3 to 2 / 3 of the volume of the ethanol absorption tower. The diameter and height ratio of the adsorption tower is 45:1000, and the interior of the adsorption tower is filled with 13X molecular sieve.

7. The nitric oxide gas purification device according to claim 1, characterized in that: A first valve is provided on the connecting pipe between the crude gas source and the extraction tower, a second valve is provided on the connecting pipe between the extraction tower and the decomposition tower, a third valve is provided on the connecting pipe between the decomposition tower and the alkali washing tower, a fourth valve is provided on the connecting pipe between the alkali washing tower and the condenser, a fifth valve is provided on the connecting pipe between the condenser and the ethanol absorption tower, a sixth valve is provided on the connecting pipe between the ethanol absorption tower and the adsorption tower, and a seventh valve is provided on the connecting pipe between the adsorption tower and the product collection unit.

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