Device and method for purifying high-purity electronic gas

Abstract

The invention belongs to the technical field of chemical engineering, and particularly relates to a purification device and method for high-purity electronic gas. The purification device for the high-purity electronic gas comprises a storage tank, a light component removal tower, a heavy component removal tower, a refined product storage tank and a waste gas absorption pool, the purification method of the high-purity electronic gas comprises the following steps: S1, removing light components of which the boiling point is lower than that of a raw material from crude electronic gas in a storage tank through a light component removal tower; s2, removing heavy components of which the boiling point is higher than that of the raw material from the material of which the light components are removed by the light component removal tower through a heavy component removal tower; and S3, analyzing and detecting the material of which the heavy components are removed by the heavy component removal tower through a gas analyzer, opening a pneumatic valve according to the types of impurities in a detection result, enabling impurity gas to enter a waste gas absorption tank through a gas separation membrane, and enabling fine gas to enter a fine storage tank. According to the gas purification device, electron gas with relatively high purity is obtained through two-stage rectification and impurity removal of the gas separation membrane, and the device is simple.

Description

Technical Field

[0001] The present application belongs to the field of chemical technology, and specifically relates to a purification device and method for high-purity electronic gas. Background Art

[0002] Electronic gas is an indispensable basic supporting source material in the development of integrated circuits, optoelectronics, microelectronics, especially in the manufacturing process of ultra-large-scale integrated circuits, liquid crystal display devices, semiconductor light-emitting devices and semiconductor materials. It is called the "blood" and "food" of the electronics industry. Its purity and cleanliness directly affect the quality, integration, specific technical indicators and yield rate of optoelectronic and microelectronic devices, and fundamentally restrict the precision and accuracy of circuits and devices. The purification of existing electronic gases is mainly achieved by combining adsorption and distillation. In actual production, impurities with boiling points close to the main components are particularly difficult to remove, requiring a higher reflux ratio. However, at higher energy consumption, the purification effect is still unsatisfactory, and the content of difficult-to-remove impurities restricts the improvement of product purity.

[0003] The Chinese invention patent with the announcement number CN113735683B discloses a purification device for electronic grade difluoromethane and a purification method thereof, the device includes a pre-reactor and a secondary distillation system connected to the pre-reactor, the pre-reactor is a bubbling reactor, and the secondary distillation system includes a light removal tower and a heavy removal tower connected in sequence. The patent first treats difluoromethane through a bubbling reactor, which can effectively reduce impurities that are difficult to remove by distillation methods, reduce the difficulty of distillation, and reduce the number of plates and reflux ratio. However, the purity of the prepared gas is 99.998%, and because the interfacial area of ​​the unit volume of the liquid phase of the bubbling reactor is small, the efficiency of gas-liquid interphase mass transfer may be limited. A Chinese utility model patent with announcement number CN213913041U discloses a fluorine-containing C4F8 electronic gas purification device, including a molecular sieve device, a multi-stage adsorption device, and a distillation device. The device removes impurities by adsorption by the molecular sieve device and multiple adsorptions by the first adsorption device, the second adsorption device to the Nth adsorption device, and then removes impurities by distillation, condensation and reboiling by the distillation device to obtain a high-purity fluorine-containing C4F8 electronic gas. Although the device is provided with a molecular sieve impurity removal device, in order to remove moisture from the gas, its actual impurity removal is still to purify the gas through multi-stage distillation.

[0004] In summary, in order to obtain high-purity electronic gas with better purity and meet the needs of industrial production, it is urgent to propose a device and method with better electronic gas purification effect. Summary of the invention

[0005] In view of the fact that the electronic gas purification device in the prior art is complicated and the purity of the purified gas is not high, the present application provides a device and method with better electronic gas purification effect.

[0006] The technical solution of this application:

[0007] In a first aspect, the present application provides a purification device for high-purity electronic gas, including a storage tank, a light removal tower, a heavy removal tower, a fine product storage tank, and an exhaust gas absorption pool;

[0008] The material storage tank is provided with a crude electronic gas inlet and a crude electronic gas outlet; the upper part of the light removal tower is provided with a light removal gas inlet, and the lower part of the light removal tower is provided with a light removal gas outlet; the lower part of the heavy removal tower is provided with a heavy removal gas inlet, and the upper part of the heavy removal tower is provided with a heavy removal gas outlet; the fine product storage tank is provided with a fine product gas collection port; the waste gas absorption tank is provided with a waste gas inlet;

[0009] The crude electronic gas outlet on the storage tank is connected to the light gas inlet of the light gas removal tower through a first pipeline, the light gas outlet of the light gas removal tower is connected to the heavy gas inlet of the heavy gas removal tower through a second pipeline, and the heavy gas outlet of the heavy gas removal tower is connected to the fine gas collection port of the fine product storage tank through a third pipeline;

[0010] The third pipeline is connected to no less than 6 gas filtration pipelines, and the gas filtration pipelines are provided with pneumatic valves and gas separation membranes. Each pneumatic valve corresponds to a gas separation membrane. The end of the gas filtration pipeline away from the third pipeline extends to the bottom of the exhaust gas absorption tank.

[0011] Preferably, a gas analyzer is connected to the top of the deweighting tower to detect the types of impurities contained in the material coming out of the deweighting tower.

[0012] Preferably, multiple layers of packing layers are obliquely arranged inside the light-removing tower and the heavy-removing tower, and the packing of the packing layer is any one of corrugated packing, mesh packing and wire mesh packing.

[0013] In a second aspect, the present application provides a method for purifying high-purity electronic gas, comprising the following steps:

[0014] Step S1. The crude electronic gas in the storage tank is passed through a light removal tower to remove light components having a lower boiling point than the crude electronic gas;

[0015] Step S2. The material having light components removed by a light removal tower is passed through a heavy removal tower to remove heavy components having a boiling point higher than that of the crude electronic gas;

[0016] Step S3. The material from which the heavy components have been removed by the deweighting tower is analyzed and tested by a gas analyzer. Based on the type and content of the impurity gas in the test results, the pneumatic valve is opened, and the impurity gas enters the waste gas absorption tank through the gas separation membrane, and the fine gas enters the fine storage tank.

[0017] Preferably, the purity of the crude electron gas is ≥99.9%, and the crude electron gas is any one of nitrogen trifluoride, tungsten hexafluoride, hydrogen chloride, silicon tetrafluoride, hydrogen fluoride, octafluorocyclobutane, hexafluoroethane, hydrogen bromide, boron trichloride, sulfur dioxide, monofluoromethane, difluoromethane, trifluoromethane, carbon monoxide, ethylene, silane and disilane.

[0018] Preferably, the gas analyzer is any one of a gas chromatograph and a hydrogen flame ion chromatograph, the inlet pressure of the gas analyzer is -20 to 20 KPa, and the types of impurity gases detected by the gas analyzer are hydrogen, oxygen, nitrogen, methane, carbon monoxide, carbon dioxide, ethane, acetylene, silicon tetrachloride and carbon tetrafluoride.

[0019] Preferably, the gas separation membrane is any one of an ion exchange membrane, an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane.

[0020] Preferably, the pressure of the waste gas absorption tank is lower than that of the fine gas storage tank.

[0021] Beneficial effects of this application:

[0022] The gas purification device used in the present application removes light components and heavy components from the crude electronic gas through continuous treatment of a light removal tower and a heavy removal tower, preliminarily ensuring the purity of the product, and uses instruments to detect the types of impurities in the gas that has been treated with light removal and heavy removal, and selectively opens pneumatic valves and gas separation membranes to remove specific impurity gases based on the types of impurity gases, thereby improving the pertinence and efficiency of purification and saving resources. Distillation and separation membranes are used to synergistically remove impurity gases from electronic gases, and the impurity content of the purified electronic gas is less than 1ppm, and the purity of the electronic gas reaches 6N level. Compared with traditional impurity removal devices, the device of the present application is not only applicable to the impurity removal of a variety of gases, but also has a simple device, is easy to operate, and can be mass-produced continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 This is a schematic diagram of the purification device of the present application.

[0024] Description of reference numerals:

[0025] 1. Storage tank; 2. First pipeline; 3. Light-removal tower; 4. Heavy-removal tower; 5. Third pipeline; 6. Gas analyzer; 7. Gas filtration pipeline; 8. Waste gas absorption tank; 9. Fine storage tank; 10. Pneumatic valve; 11. Gas separation membrane; 12. Second pipeline. DETAILED DESCRIPTION

[0026] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present application are described in detail below in combination with the preferred embodiments and drawings.

[0027] Equipment Examples

[0028] Provided is a high-purity electronic gas purification device, comprising a storage tank 1, a light removal tower 3, a heavy removal tower 4, a fine product storage tank 9 and a waste gas absorption pool 8;

[0029] The storage tank 1 is used to store the crude electronic gas, and the storage tank 1 is provided with a crude electronic gas inlet and a crude electronic gas outlet; the light removal tower 3 is used to remove light components with a lower boiling point than the crude electronic gas, and the light removal tower 3 is provided with a light removal gas inlet at the top and a light removal gas outlet at the bottom;

[0030] The deweighting tower 4 is used to remove heavy components with a higher boiling point than the crude electronic gas. A deweighting gas inlet is provided at the lower portion of the deweighting tower 4, and a deweighting gas outlet is provided at the upper portion of the deweighting tower 4. A gas analyzer 6 is connected to the top of the deweighting tower 4 to detect the types of impurities contained in the material coming out of the deweighting tower 4, wherein the gas analyzer 6 can be any one of a gas chromatograph and a hydrogen flame ion chromatograph.

[0031] The fine product storage tank 9 is used to store the fine product gas after impurities are removed, and the fine product storage tank 9 is provided with a fine product gas collection port; the waste gas absorption pool 8 is used to absorb impurities in the gas after the crude electronic gas is de-lightened and de-heavyened, and the waste gas absorption pool 8 is provided with a waste gas inlet;

[0032] The crude electronic gas outlet on the storage tank 1 is connected to the light gas inlet of the light gas removal tower 3 through the first pipeline 2, the light gas outlet of the light gas removal tower 3 is connected to the heavy gas inlet of the heavy gas removal tower 4 through the second pipeline 12, and the heavy gas outlet of the heavy gas removal tower 4 is connected to the fine gas collection port of the fine product storage tank 9 through the third pipeline 5;

[0033] The third pipeline 5 is connected to no less than 6 gas filtration pipelines 7, and the gas filtration pipelines 7 are provided with pneumatic valves 10 and gas separation membranes 11. Each pneumatic valve 10 corresponds to a gas separation membrane 11. The end of the gas filtration pipeline 7 away from the third pipeline 5 extends to the bottom of the exhaust gas absorption tank 8, wherein the gas separation membrane can be any one of an ion exchange membrane, an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane.

[0034] Multiple packing layers are obliquely arranged inside the light-removing tower 3 and the heavy-removing tower 4, wherein the packing of the packing layer can be any one of corrugated packing, mesh packing and wire mesh packing.

[0035] Examples 1-3 provide a method for purifying high-purity electronic gas, using the equipment of the equipment example, the only difference being the operating conditions and the crude electronic gas. The gas analyzer 6 used in Examples 1 to 3 is a gas chromatograph, and the gas separation membrane 11 is an ultrafiltration membrane.

[0036] Example 1

[0037] This embodiment provides a method for purifying boron trichloride with a purity of 99.9%, wherein the impurity gases in the boron trichloride include hydrogen, oxygen, nitrogen, methane, carbon monoxide and carbon dioxide.

[0038] The specific steps are as follows:

[0039] Step S1. The crude boron trichloride gas is pressed into the storage tank 1, and the crude boron trichloride gas enters the light removal tower 3 through the first pipeline 2 to remove light components with a lower boiling point than the crude boron trichloride gas. The operating temperature of the light removal tower 3 is 50°C and the pressure is 0.30MPa;

[0040] Step S2. The components coming out of the light removal tower 3 enter the heavy removal tower 4 through the second pipeline 12 to remove the heavy components with a higher boiling point than the crude boron trichloride gas. The operating temperature of the light removal tower 3 is 40°C and the pressure is 0.20MPa.

[0041] Step S3. The material coming out of the top of the de-weighting tower 4 is analyzed and detected by the gas analyzer 6. The pressure of the sample is 0MPa. The content of each impurity in the gas finally coming out of the de-weighting tower 3 and the de-weighting tower 4 is detected, as shown in Table 1. According to the results of Table 1, it is found that the content of hydrogen and carbon dioxide gas is high. The pneumatic valves 10 corresponding to hydrogen and carbon dioxide on the third pipeline 5 are opened respectively. Hydrogen and carbon dioxide are separated from the gas separation membrane 11 and enter the waste gas absorption tank 8 through the gas filtration pipeline 7. The fine boron trichloride gas from which the gas impurities are removed by the gas separation membrane 11 is collected in the fine storage tank 9, and the content of each impurity in the fine storage tank 9 is detected as shown in Table 2. The purity of the boron trichloride gas is 99.9999%.

[0042] Table 1

[0043] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> CO <![CDATA[CO2]]> 0.23 ppm 0.01 ppm 0.03 ppm <0.01 ppm <0.01 ppm 0.12 ppm

[0044] Table 2

[0045] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> CO <![CDATA[CO2]]> 0.03 ppm 0.01 ppm 0.03 ppm <0.01 ppm <0.01 ppm 0.03 ppm

[0046] Example 2

[0047] This embodiment provides a method for purifying hydrogen chloride with a purity of 99.9%, wherein the impurity gases in hydrogen, oxygen, nitrogen, methane, carbon monoxide and carbon dioxide include hydrogen, oxygen, nitrogen, methane, carbon monoxide and carbon dioxide.

[0048] The specific steps are as follows:

[0049] Step S1. The crude hydrogen chloride gas is pressed into the storage tank 1, and the crude hydrogen chloride gas enters the light removal tower 3 through the first pipeline 2 to remove light components with a lower boiling point than the crude hydrogen chloride gas. The operating temperature of the light removal tower 3 is -10°C and the pressure is 2.30MPa;

[0050] Step S2. The components coming out of the light removal tower 3 enter the heavy removal tower 4 through the second pipeline 12 to remove the heavy components with a higher boiling point than the crude hydrogen chloride gas. The operating temperature of the light removal tower 3 is -5°C and the pressure is 2.00 MPa;

[0051] Step S3. The material coming out of the top of the de-weighting tower 4 is analyzed and detected by the gas analyzer 6. The pressure of the sample is 0MPa. The content of each impurity in the gas finally coming out of the de-weighting tower 3 and the de-weighting tower 4 is detected, as shown in Table 3. According to the results in Table 3, it is found that the content of three impurity gases, hydrogen, oxygen and carbon dioxide, is relatively high. The pneumatic valves 10 corresponding to hydrogen, oxygen and carbon dioxide on the third pipeline 5 are opened respectively. Hydrogen, oxygen and carbon dioxide are separated from the gas separation membrane 11 and enter the waste gas absorption tank 8 through the gas filtration pipeline 7. The fine hydrogen chloride gas from which the gas impurities are removed by the gas separation membrane 11 is collected into the fine storage tank 9, and the content of each impurity in the fine storage tank 9 is detected as shown in Table 4. The purity of the hydrogen chloride gas is 99.9999%.

[0052] Table 3

[0053] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> CO <![CDATA[CO2]]> 0.52 ppm 0.08 ppm 0.07 ppm <0.01 ppm <0.01 ppm 0.44 ppm

[0054] Table 4

[0055] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> CO <![CDATA[CO2]]> 0.04 ppm <0.01 ppm 0.06 ppm <0.01 ppm <0.01 ppm 0.06 ppm

[0056] Example 3

[0057] This embodiment provides a method for purifying difluoromethane with a purity of 99.9%, wherein the impurity gases in the difluoromethane include hydrogen, oxygen, nitrogen, methane, carbon monoxide and carbon dioxide.

[0058] The specific steps are as follows:

[0059] Step S1. The crude difluoromethane gas is pressed into the storage tank 1, and the crude difluoromethane gas enters the light-removal tower 3 through the first pipeline 2 to remove light components with a lower boiling point than the crude difluoromethane gas. The operating temperature of the light-removal tower 3 is 10° C. and the pressure is 0.9 MPa;

[0060] Step S2. The components coming out of the light removal tower 3 enter the heavy removal tower 4 through the second pipeline 12 to remove the heavy components with a higher boiling point than the crude difluoromethane gas. The operating temperature of the light removal tower 3 is 0°C and the pressure is 0.7MPa.

[0061] Step S3. The material coming out of the top of the de-weighting tower 4 is analyzed and detected by the gas analyzer 6. The pressure of the sample is 0MPa. The content of each impurity in the gas finally coming out of the de-weighting tower 3 and the de-weighting tower 4 is detected, as shown in Table 5. According to the results of Table 5, it is found that the content of the two impurity gases ethane and ethylene is relatively high. The pneumatic valves 10 corresponding to ethane and ethylene on the third pipeline 5 are opened respectively. Ethane and ethylene are separated from the gas separation membrane 11 and enter the waste gas absorption tank 8 through the gas filtration pipeline 7. The fine difluoromethane gas from which the gas impurities are removed by the gas separation membrane 11 is collected in the fine storage tank 9, and the content of each impurity in the fine storage tank 9 is detected as shown in Table 6. The purity of the difluoromethane gas is 99.9999%.

[0062] Table 5

[0063] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> <![CDATA[C2H6]]> <![CDATA[C2H4]]> 0.02 ppm 0.08 ppm 0.07 ppm <0.01 ppm 1.2 ppm 0.6 ppm

[0064] Table 6

[0065] <![CDATA[H2]]> <![CDATA[O2+Ar]]> <![CDATA[N2]]> <![CDATA[CH4]]> <![CDATA[C2H6]]> <![CDATA[C2H4]]> 0.02 ppm 0.08 ppm 0.07 ppm <0.01 ppm 0.06 ppm 0.02 ppm

[0066] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A purification device for high-purity electronic gas, characterized in that: Including storage tanks, light removal towers, heavy removal towers, fine storage tanks and waste gas absorption pools; The material storage tank is provided with a crude electronic gas inlet and a crude electronic gas outlet; the upper part of the light removal tower is provided with a light removal gas inlet, and the lower part of the light removal tower is provided with a light removal gas outlet; the lower part of the heavy removal tower is provided with a heavy removal gas inlet, and the upper part of the heavy removal tower is provided with a heavy removal gas outlet; the fine product storage tank is provided with a fine product gas collection port; the waste gas absorption tank is provided with a waste gas inlet; The crude electronic gas outlet on the storage tank is connected to the light gas inlet of the light gas removal tower through a first pipeline, the light gas outlet of the light gas removal tower is connected to the heavy gas inlet of the heavy gas removal tower through a second pipeline, and the heavy gas outlet of the heavy gas removal tower is connected to the fine gas collection port of the fine product storage tank through a third pipeline; The third pipeline is connected to no less than 6 gas filtration pipelines, and the gas filtration pipelines are provided with pneumatic valves and gas separation membranes. Each pneumatic valve corresponds to a gas separation membrane. The end of the gas filtration pipeline away from the third pipeline extends to the bottom of the exhaust gas absorption tank.

2. A high-purity electronic gas purification device according to claim 1, characterized in that: A gas analyzer is connected to the top of the deweighting tower to detect the types of impurities contained in the material coming out of the deweighting tower.

3. The high-purity electronic gas purification device according to claim 1, characterized in that: The light-removing tower and the heavy-removing tower are internally provided with multiple layers of fillers which are inclined, and the fillers of the fillers in the fillers layers are any one of corrugated fillers, mesh fillers and wire mesh fillers.

4. A method for purifying high-purity electronic gas, based on a high-purity electronic gas purification device according to any one of claims 1 to 3, characterized in that: The steps include: Step S1. The crude electronic gas in the storage tank is passed through a light removal tower to remove light components having a lower boiling point than the crude electronic gas; Step S2. The material having light components removed by a light removal tower is passed through a heavy removal tower to remove heavy components having a boiling point higher than that of the crude electronic gas; Step S3. The material from which the heavy components have been removed by the deweighting tower is analyzed and tested by a gas analyzer. Based on the type and content of the impurity gas in the test results, the pneumatic valve is opened, and the impurity gas enters the waste gas absorption tank through the gas separation membrane, and the fine gas enters the fine storage tank.

5. The method for purifying high-purity electronic gas according to claim 4, characterized in that: The purity of the crude electronic gas is ≥99.9%, and the crude electronic gas is any one of nitrogen trifluoride, tungsten hexafluoride, hydrogen chloride, silicon tetrafluoride, hydrogen fluoride, octafluorocyclobutane, hexafluoroethane, hydrogen bromide, boron trichloride, sulfur dioxide, monofluoromethane, difluoromethane, trifluoromethane, carbon monoxide, ethylene, silane and disilane.

6. The method for purifying high-purity electronic gas according to claim 4, characterized in that: The gas analyzer is any one of a gas chromatograph and a hydrogen flame ion chromatograph. The inlet pressure of the gas analyzer is -20 to 20 KPa. The impurity gases detected by the gas analyzer are hydrogen, oxygen, nitrogen, methane, carbon monoxide, carbon dioxide, ethane, acetylene, silicon tetrachloride and carbon tetrafluoride.

7. The method for purifying high-purity electronic gas according to claim 4, characterized in that: The gas separation membrane is any one of an ion exchange membrane, an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane.

8. The method for purifying high-purity electronic gas according to claim 4, characterized in that: The pressure of the waste gas absorption pool is lower than that of the fine storage tank.

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