A device and process for preparing ultra-high purity hydrogen chloride gas for semiconductors

Abstract

The invention discloses a preparation device and process for ultra-high purity hydrogen chloride gas for semiconductors. With industrial product gas as raw material, a combination of polymer permeable membrane, metal cation exchange resin, rare earth metal compound dehydration and high-pressure distillation is adopted to remove CO2 impurities in components to below 0.1ppm and metal ion content to below 10ppt. The preparation process gets rid of the dependence of the prior art on raw materials, produces ultra-high purity hydrogen chloride gas and hydrogen chloride gas of various qualities at the same time, reduces tail gas and is easy to handle, and is suitable for industrial promotion.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-high purity gas preparation, and in particular to a device and process for preparing ultra-high purity hydrogen chloride gas for semiconductors. Background Art

[0002] With the development of semiconductor electronic manufacturing industry, the purity requirements for ultra-high purity gases used in semiconductor manufacturing (hereinafter referred to as semiconductor electronic gases) are getting higher and higher. The lower the content of impurities such as total hydrocarbons (THC), H2O, CO2 and metal ions, the better. At the same time, the market demand for semiconductor electronic gases is also growing. However, the domestic semiconductor electronic gas market is currently mainly dependent on imports, and the localization of 6-7N ultra-high purity semiconductor electronic gases is imminent.

[0003] Chinese patent document CN107848798A describes a method for producing hydrogen chloride. In the purification process, hydrochloric acid absorption, hydrochloric acid analysis, and concentrated sulfuric acid drying methods are required. This process will produce a lot of wastewater. At the same time, the absorption and analysis processes will cause excessive moisture in the raw hydrogen chloride. The concentrated sulfuric acid has limited effect in removing water, and pollutants such as dilute sulfuric acid will be produced.

[0004] Chinese patent document CN208200380U describes a device for preparing ultrapure hydrogen chloride, which requires first purifying the raw materials hydrogen and chlorine, and then introducing them into a catalytic reactor for synthesis, using a variety of complex raw material purification devices and catalytic reaction devices.

[0005] Chinese patent document CN106044710A describes a method for purifying electronic grade hydrogen chloride, which uses a complex ion exchange resin for adsorbing hydrogen and carbon dioxide impurities to adsorb hydrogen and carbon dioxide impurities in hydrogen chloride, but cannot effectively remove other impurities in hydrogen chloride.

[0006] Chinese patent document CN107746040A describes a process and equipment for refining hydrogen chloride using by-product gas from the production of trichloroethylene. The raw material used is hydrogen chloride, a by-product tail gas with a relatively complex impurity content. It is highly dependent on the raw material production process and also causes many unknown impurities in the product.

[0007] Chinese patent document CN 1511780 A describes a method for preparing electronic grade hydrogen chloride, which requires the use of petrochemical tail gas (hydrogen chloride, an intermediate byproduct of PVC production by ethylene process), which contains a large amount of acetylene impurities and requires the use of mercury catalyst to catalyze the reaction to remove the acetylene impurities, resulting in the generation of solid hazardous waste. At the same time, the impurity composition in the tail gas is relatively complex, which is not conducive to the purity of the final product.

[0008] Therefore, it is necessary to propose a device and process for preparing ultra-high purity hydrogen chloride gas for semiconductors to at least solve one of the defects of various processing methods in the prior art. Summary of the invention

[0009] The purpose of the present invention is to provide a device and process for preparing ultra-high purity hydrogen chloride gas for semiconductors, which uses industrial product gas as raw material and adopts a combination of polymer permeable membrane, metal cation exchange resin, rare earth metal compound dehydration and high-pressure distillation to solve the technical problems existing in the existing process, such as the limitation of raw material selection, complex process flow and generation of waste acid, waste water, heavy metal solid hazardous waste, etc.

[0010] In view of this, the scheme of the present invention is:

[0011] A process for preparing ultra-high purity hydrogen chloride gas for semiconductor use comprises the following steps:

[0012] S1. After the industrial hydrogen chloride gas is dehydrated for the first time, it is liquefied and subjected to the first distillation to obtain a light fraction;

[0013] S2. The obtained light fraction is condensed and then subjected to gas-liquid separation, and the obtained liquid phase is subjected to a second dehydration;

[0014] S3. After the water is removed, the liquid phase is passed through a permeable membrane to remove CO2 and a metal cation exchange resin to remove heavy metals to obtain ultra-high purity hydrogen chloride gas.

[0015] According to an embodiment of the present invention, after the gas after the second water removal in step S2 is subjected to a second distillation, the bottom components enter step S3; the top components of the second distillation tower are fully refluxed after condensation and gas-liquid separation to remove light component gases.

[0016] Furthermore, the second distillation conditions are as follows: pressure 3.5-5.5 MPa, tower top temperature 9-22°C, tower bottom temperature 12-27°C.

[0017] According to an embodiment of the present invention, the first water removal uses an acidic molecular sieve, and the second water removal uses aluminosilicate-yttrium silicate.

[0018] According to an embodiment of the present invention, the metal cation exchange resin is a strongly acidic styrene-based cation exchange resin.

[0019] According to an embodiment of the present invention, the distillation pressure in step S1 is 4.0-6.0 MPa, the tower top temperature is controlled at 12-25°C, and the tower bottom temperature is controlled at 15-30°C.

[0020] A device for preparing ultra-high purity hydrogen chloride gas for semiconductors comprises a first purifier, a first distillation tower, a first condenser, a first gas-liquid separator, a second purifier, a third purifier and a fourth purifier which are connected in sequence; the first purifier and the second purifier are respectively used to remove water in the hydrogen chloride gas, the third purifier is used to remove CO2, and the fourth purifier is used to remove heavy metals; the first distillation tower is used to remove heavy components, and the first gas-liquid separator is used to remove gas phase components; the industrial hydrogen chloride gas is dehydrated by the second purifier and then distilled by the first distillation tower to obtain light components, the light components are condensed by the first condenser to remove gas phase, and then are removed from impurities by the third purifier and the fourth purifier in sequence to obtain ultra-high purity hydrogen chloride gas.

[0021] According to an embodiment of the present invention, a first reflux pipe is provided at the bottom of the first gas-liquid separator and is connected to the top of the first distillation tower.

[0022] According to an embodiment of the present invention, the device also includes a second distillation tower for removing light components, a second condenser, and a second gas-liquid separator; the output end of the second purifier is connected to the feed inlet of the second distillation tower, the top of the second distillation tower is connected to the second condenser, the second condenser is connected to the second gas-liquid separator, and the upper part of the second gas-liquid separator is provided with a second crude product extraction pipe, and the lower part is provided with a second reflux pipe and connected to the top of the second distillation tower.

[0023] According to an embodiment of the present invention, a first crude product extraction pipe is further provided at the bottom of the first gas-liquid separator; and a third crude product extraction pipe is provided at the third purifier.

[0024] Compared with the prior art, the present invention has the following effects:

[0025] 1. The present invention uses a rare earth metal compound purifier to remove moisture to below 0.1ppm, solving the problem that hydrogen chloride and water are difficult to be completely separated due to hydrogen bonds formed in the distillation operation; the polymer permeable membrane technology is used to solve the technical problem that CO2 impurities in hydrogen chloride are difficult to remove, greatly reducing the reflux ratio and energy consumption of the distillation operation; the metal cation exchange resin can efficiently remove metal impurities, solving the inefficiency problem of simple distillation in the distillation operation to remove metal impurities; the combination of the above methods ensures the purity of the product 6N-7N;

[0026] 2. The present invention uses purchased or independently synthesized hydrogen chloride as raw material, which is low in price, widely available, and has little limitation in industrial application;

[0027] 3. While generating ultra-high purity target gas, the present invention can use the hydrogen chloride gas containing high-boiling substances and low-boiling substances discharged from multiple separators or purifiers as a low-grade raw material for chemical industry, and comprehensively recycle and utilize it without exhaust gas emission;

[0028] 4. The present invention can realize continuous operation of the device by comprehensively adopting rare earth metal compound dehydration, polymer permeable membrane, metal cation exchange resin and high-pressure distillation integrated technology. The operating unit containing the filler can be set to switch to form a continuous and stable fully automatic control process, which ensures the stability of product quality and the consistency of products from batch to batch, and the product recovery rate is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is an overall schematic diagram of the device for preparing ultra-high purity hydrogen chloride gas for semiconductors according to the present invention.

[0031] Among them: 1. synthesis furnace; 2. first purifier; 3. compressor; 4. first distillation tower; 5. first condenser; 6. first gas-liquid separator; 7. second purifier; 8. second distillation tower; 9. second condenser; 10. second gas-liquid separator; 11. third purifier; 12. fourth purifier; 41. light fraction pipeline; 42. heavy fraction discharge pipeline; 61. first reflux pipe; 62. first liquid separation discharge pipe; 63. tail gas extraction pipe; 64. first crude product extraction pipe; 101. second crude product extraction pipe; 102. second reflux pipe; 111. third crude product extraction pipe. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and beneficial technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the present invention, not for limiting the present invention.

[0033] It should be understood that the orientations or positional relationships indicated by terms such as “upper”, “lower”, “top”, “bottom”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be determined according to the specific circumstances.

[0035] Industrial hydrogen chloride gas contains a variety of impurity gases including CO2, H2, N2, O2, CO, H2O, CH4 and Cl2, as well as a variety of metal impurities including iron, nickel, copper, cobalt, manganese and chromium. Electronic grade hydrogen chloride gas (6N-7N) must be obtained, and the above impurities must be effectively removed and new impurities must be avoided.

[0036] The present invention provides a process for preparing ultra-high purity hydrogen chloride gas for semiconductors, comprising the following steps:

[0037] 1. After the industrial hydrogen chloride gas is dehydrated by an acidic molecular sieve, it is compressed to liquefaction and subjected to the first distillation to obtain a light fraction; the pressure of the first distillation is 4.0-6.0 MPa, the tower top temperature is controlled at 12-25°C, and the tower bottom temperature is controlled at 15-30°C;

[0038] 2. The light fraction obtained from the first distillation is condensed and then separated into gas and liquid, and the obtained liquid phase is subjected to a second dehydration using silica-alumina-yttrium silicate;

[0039] 3. In order to further remove light components, the gas after the second water removal is subjected to a second distillation, and the bottom components are subjected to a permeable membrane to remove CO2 and a metal cation exchange resin to remove heavy metals to obtain ultra-high purity hydrogen chloride gas; the top components of the second distillation tower are condensed and subjected to gas-liquid separation to remove heavy components and then fully refluxed; the second distillation conditions are as follows: pressure 3.5-5.5MPa, tower top temperature 9-22°C, and tower bottom temperature 12-27°C.

[0040] In the present invention, the polymer permeable membrane can be a modified polyimide hollow fiber membrane, and the average pore size per unit area is between the sizes of hydrogen chloride and carbon dioxide molecules, such as about 0.30nm, which can achieve the separation of CO2; the metal cation exchange resin can be an alkali metal (sodium / potassium) styrene-based strong acid cation exchange resin to achieve the adsorption and removal of heavy metal ions.

[0041] The present invention adopts a rare earth metal compound purifier to remove water to below 0.1ppm, thereby solving the problem that hydrogen chloride is difficult to be completely separated from water due to hydrogen bonds formed during distillation operation; adopts polymer permeable membrane technology to solve the technical problem that CO2 impurities in hydrogen chloride are difficult to remove, thereby greatly reducing the reflux ratio and energy consumption of distillation operation; metal cation exchange resin can efficiently remove metal impurities, thereby solving the inefficient problem that metal impurity removal is only simple distillation during distillation operation; the combination of the above methods can obtain high-purity hydrogen chloride with a final purity of 6N-7N.

[0042] The present invention also provides an ultra-high purity hydrogen chloride gas preparation device for semiconductors, comprising a synthesis furnace 1, a first purifier 2, a compressor 3, a first distillation device 4, a first condenser 5, a first gas-liquid separator 6, a second purifier 7, a second distillation tower 8 and a second condenser 9 which are sequentially connected through pipelines. Wherein: the lower part of the synthesis furnace 1 is respectively provided with pipelines for introducing hydrogen and chlorine, the synthesis gas outlet at the upper part of the synthesis furnace 1 is connected to the lower part of the first purifier 2, the upper part of the first purifier 2 is connected to the input end of the compressor 3, the output end of the compressor 3 is connected to the feed port of the first distillation device 4, the lower part of the first distillation device 4 is provided with a heavy component discharge pipeline 42, the top is provided with a light fraction pipeline 41 connected to the first condenser 5, the first condenser 5 is further connected to the middle part of the first gas-liquid separator 6, the upper part of the first gas-liquid separator 6 is provided with a tail gas extraction pipe 63, the lower part is provided with a first reflux pipe 61, a first crude product extraction pipe 64 and a first liquid separation discharge pipe 62, the first reflux pipe 61 is connected to the top of the first distillation device 4 to improve the purity of the target product obtained after distillation, and the first liquid separation discharge pipe 62 is connected to the lower part of the second purifier 7. In order to further improve the purity and separate the impurity components, the components purified by the second purifier 7 are connected to the second distillation tower 8 for further distillation, the upper part of the second purifier 7 is connected to the feed port of the second distillation tower 8, the top of the second distillation tower 8 is connected to the second condenser 9 and further connected to the air inlet end of the second gas-liquid separator 10; the top of the second gas-liquid separator 10 is provided with a second crude product extraction pipe 101, and the bottom is provided with a second reflux pipe 102 connected to the top of the second distillation tower 8 for full reflux, so as to further improve the purity of the target component after distillation.

[0043] On the basis of the above, the product after secondary distillation in the second distillation tower 8 is taken out from the bottom of the tower, the bottom of the second distillation tower 8 is connected to the bottom of the third purifier 11, and the top of the third purifier 11 is connected to the top of the fourth purifier.

[0044] In the present invention, the first gas-liquid separator 6 and the second gas-liquid separator 10 are both common separators for separating gas phase and liquid phase, such as using wire mesh separation to achieve gas phase escaping upward and liquid phase bottom extraction. The first distillation tower 4 and the second distillation tower 8 are common distillation towers, which use the difference in vapor pressure of each component at the same temperature to achieve separation of light components and heavy components.

[0045] In the present invention, the first purifier 2 is a common dehydration device, such as a device with an acidic molecular sieve as filler, and dehydration is achieved through the strong adsorption of the molecular sieve, such as an alumina-silicate molecular sieve with a particle diameter of 5 mm; the second purifier 7 is a dehydration device filled with small-pore aluminosilicate-yttrium silicate, and dehydration is achieved through the dual effects of the filler itself having a strong adsorption effect and generating a crystalline compound when it comes into contact with water; the third purifier 11 is provided with a polymer permeable membrane, which is a modified polyimide hollow fiber membrane, and the average pore size per unit area is between the size of hydrogen chloride and carbon dioxide molecules, such as about 0.30 nm, through the bottom feeding, the hydrogen chloride gas that passes through the permeable membrane is discharged along the top, and the CO2 gas that cannot pass through the permeable membrane and a small amount of hydrogen chloride gas are discharged along the side, thereby separating CO2; the fourth purifier 12 is filled with a metal cation exchange resin, such as an alkali metal (sodium / potassium) styrene-based strong acidic cation exchange resin to achieve adsorption and removal of heavy metal ions.

[0046] In the present invention, according to conventional designs in the art, the ultra-high purity hydrogen chloride gas preparation device further includes valves for controlling the opening and closing of the pipeline and electrical instruments for automatic control. In addition, the first purifier 2, the second purifier 7, the third purifier 11 and the fourth purifier 12 containing fillers or special materials can be arranged in pairs, and the purity of the gas can be finally obtained through real-time detection. When in use, the standby purifier is automatically switched to maintain the reliable operation of the device unit and thus maintain the stability of product quality.

[0047] Based on the above-mentioned preparation device, the present invention proposes a preparation process of ultra-high purity hydrogen chloride gas for semiconductors.

[0048] Hydrogen and chlorine from industrial products enter the synthesis furnace 1 in the form of gas, the molar ratio of chlorine to hydrogen is 1:1.03-1.08, the pressure of the synthesis furnace is 0.005-0.5MPa, the synthesized gas enters the first purifier 2, the moisture content in the gas is removed to below 1ppm, the purified gas from the first purifier 2 enters the compressor 3 for pressurization, the outlet pressure of the compressor 3 is 4.0-7.5MPa; the outlet gas of the compressor 3 is transported to the first distillation tower 4 through a pipeline, the rising hydrogen chloride gas is extracted at the top of the first distillation tower 4 and enters the first condenser 5, the condensation temperature is set below the boiling point of hydrogen chloride, and the condensed liquid component enters the first gas-liquid separator 6. The uncondensed gas in the first gas-liquid separator 6 is emptied into the tail gas treatment system; part of the condensate is refluxed to the top of the first distillation tower 4, and exchanges mass and heat with the rising hydrogen chloride gas in the first distillation tower 4 to achieve the purpose of separating and removing high-boiling impurity components; part of the condensate is extracted as an industrial-grade product hydrogen chloride and enters its filling system; the liquid containing heavy component impurities extracted from the bottom of the first distillation tower 4 is discharged to the tail gas treatment system. The operating pressure of the first distillation tower 4 is controlled at 4.0-6.0MPa, the top temperature is controlled at 12-25℃, and the bottom temperature is controlled at 15-30℃. The condensate extracted from the first gas-liquid separator 6 enters the second purifier 7 containing high-efficiency rare earth metal compounds to remove the water in the hydrogen chloride to below 0.1ppm. The material after water removal enters the second distillation tower 8, and the hydrogen chloride gas heated by the electric heating jacket, heat-conducting oil or steam in the tower bottom rises to the top of the tower, and enters the second gas-liquid separator 10 after condensation by the second condenser 9. The non-condensable gas in the second gas-liquid separator 10 is emptied to the industrial-grade product recovery system along the second crude product extraction pipe 101, and the liquid in the second gas-liquid separator 10 is fully refluxed to the second distillation tower 8 through the second reflux pipe 102 to continue the mass and heat exchange with the rising hydrogen chloride gas in the second distillation tower 8, so as to achieve the purpose of separating and purifying the low-boiling impurity components. The operating pressure of the second distillation tower 8 is controlled at 3.5-5.5MPa, the tower top temperature is controlled at 9-22°C, and the tower bottom temperature is controlled at 12-27°C. The material extracted from the bottom of the second distillation tower 8 enters the third purifier 11 using a polymer permeable membrane to remove the CO2 impurity component to less than 0.1ppm, and CO2 and part of the escaped hydrogen chloride gas are extracted from the third crude product extraction pipe 111 set at the side of the third purifier 11. The gas after CO2 removal is discharged from the top of the third purifier 11 and enters the fourth purifier 12 filled with metal cation exchange resin to remove the metal ion content in the material to less than 10ppt. The material after metal ion removal is output from the bottom of the fourth purifier 12 and enters the product analysis and filling system as the final ultra-high purity hydrogen chloride for semiconductors.

[0049] The hydrogen and chlorine described in the present invention are industrial grade, such as industrial grade gases with a volume ratio of more than 99%. In this embodiment, hydrogen and chlorine are synthesized in a synthesis furnace, and industrial grade hydrogen chloride gas can also be directly selected, such as a volume ratio of more than 95%.

[0050] The following are examples of the preparation process of the present invention under different production conditions to demonstrate the effect achieved by the above technical solution of the present invention.

[0051] Example 1

[0052] S1. The industrial hydrogen chloride gas is dehydrated to less than 1 ppm by the first purifier 3, compressed to liquefaction, and passed through the first distillation tower 4 to obtain a light fraction; the pressure of the first distillation tower 4 is 4.0 MPa, the tower top temperature is controlled at 12°C, and the tower bottom temperature is controlled at 15°C;

[0053] S2. The light fraction from the top of the first distillation tower 4 enters the first gas-liquid separator 6 after passing through the first condenser 5, and the resulting liquid phase enters the second purifier 7 for a second water removal;

[0054] S3. The gas after the second water removal enters the second distillation tower 8 for further distillation, and the heavy components in the bottom of the tower are purified by the third purifier 11 and the fourth purifier 12 in turn to obtain ultra-high purity hydrogen chloride gas; the top components of the second distillation tower 8 are completely refluxed after the light component gas is removed by the second condenser 9 and the second gas-liquid separator 10; the distillation conditions of the second distillation tower 8 are pressure 3.5MPa, tower top temperature 9°C, and tower bottom temperature 12°C.

[0055] Example 2

[0056] The same industrial hydrogen chloride gas as in Example 1 is used, and the purification method and steps are the same as in Example 1, except that the conditions of the first distillation tower 4 are 4.6 MPa, the top temperature is 16°C, and the bottom temperature is 21°C; the pressure of the second distillation tower 8 is 4.4 MPa, the top temperature is 15°C, and the bottom temperature is 19°C.

[0057] Example 3

[0058] The same industrial hydrogen chloride gas as in Example 1 is used, and the purification method and steps are the same as in Example 1, except that the pressure of the first distillation tower 4 is 6.0 MPa, the top temperature is 25°C, and the bottom temperature is 30°C; the pressure of the second distillation tower 8 is 5.5 MPa, the top temperature is 22°C, and the bottom temperature is 27°C.

[0059] Example 4

[0060] The same industrial hydrogen chloride gas as in Example 1 is used, and the purification method and steps are the same as in Example 1, except that the pressure of the first distillation tower 4 is 5.0 MPa, the top temperature is 20°C, and the bottom temperature is 25°C; the pressure of the second distillation tower 8 is 5.5 MPa, the top temperature is 24°C, and the bottom temperature is 28°C; in addition, the crude product is directly extracted from the top of the second distillation tower 8, and there is no second condenser 9 and second gas-liquid separator 10.

[0061] Example 5

[0062] Industrial chlorine and hydrogen were synthesized at a molar ratio of 1:1.03 under a pressure of 0.005 MPa, and the synthesized gas was purified by the method of Example 2.

[0063] Example 6

[0064] Industrial chlorine and hydrogen were synthesized at a molar ratio of 1:1.08 under a pressure of 0.1 MPa, and the synthesized gas was purified by the method of Example 2.

[0065] Example 7

[0066] Industrial chlorine and hydrogen were synthesized at a molar ratio of 1:1.05 under a pressure of 0.5 MPa, and the synthesized gas was purified by the method of Example 2.

[0067] Experimental example

[0068] The gas components and purity of the key operating units of the above Examples 1-6 were measured, and the results are shown in Tables 1-6.

[0069] The names of the streams corresponding to different numbers are as follows: A is the feed to the first distillation tower 4; B is the heavy component discharge from the first distillation tower 4; C is the discharge from the first crude product extraction pipe; D is the feed to the second distillation tower 8; E is the discharge from the second distillation tower 8; F is the discharge from the second crude product extraction pipe; G is the feed to the fourth purifier 12; and H is the discharge from the final finished product.

[0070] Table 1: Corresponding test results of each stream in Examples 1-6

[0071]

[0072] It can be seen from Tables 1-6 above that electronic grade ultra-high purity hydrogen chloride gas can be obtained by using industrial hydrogen chloride gas or synthesizing hydrogen chloride according to the conditions proposed by the present invention and then purified by the purification method provided by the present invention, and various levels of industrial grade hydrogen chloride can be obtained, thereby reducing the emission of tail gas.

[0073] The present invention is not limited to what is described in the specification and implementation modes, and therefore additional advantages and modifications can be easily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein.

Claims

1. A process for preparing ultra-high purity hydrogen chloride gas for semiconductor use, characterized in that: The steps include: S1. After the industrial hydrogen chloride gas is dehydrated for the first time, it is liquefied and subjected to the first distillation to obtain a light fraction; S2. The obtained light fraction is condensed and then subjected to gas-liquid separation, and the obtained liquid phase is subjected to a second dehydration; S3. The liquid phase after dehydration is passed through a permeable membrane to remove CO2 and a metal cation exchange resin to remove heavy metals to obtain ultra-high purity hydrogen chloride gas; After the gas after the second water removal in step S2 is subjected to a second distillation, the bottom components enter step S3; the top components of the second distillation tower are condensed, gas-liquid separated to remove light component gas, and then fully refluxed; The first water removal adopts acidic molecular sieve, and the second water removal adopts aluminosilicate-yttrium silicate.

2. The preparation process according to claim 1, characterized in that: The second distillation conditions are: pressure 3.5-5.5 MPa, tower top temperature 9-22°C, tower bottom temperature 12-27°C.

3. The preparation process according to claim 1, characterized in that: The metal cation exchange resin is a strongly acidic styrene-based cation exchange resin.

4. The preparation process according to claim 1, characterized in that: The distillation pressure in step S1 is 4.0-6.0 MPa, the tower top temperature is controlled at 12-25°C, and the tower bottom temperature is controlled at 15-30°C.

5. A preparation device for implementing the preparation process according to any one of claims 1 to 4, characterized in that: The invention comprises a first purifier (2), a first distillation tower (4), a first condenser (5), a first gas-liquid separator (6), a second purifier (7), a third purifier (11) and a fourth purifier (12) which are connected in sequence; the first purifier (2) and the second purifier (7) are respectively used to remove water from the hydrogen chloride gas, the third purifier (11) is used to remove CO2, and the fourth purifier is used to remove heavy metals; the first distillation tower (4) is used to remove heavy components, and the first gas-liquid separator (6) is used to remove gaseous components; the industrial hydrogen chloride gas is dehydrated by the first purifier (2) and then distilled by the first distillation tower (4) to obtain light components; the light components are condensed by the first condenser (5) to remove gaseous phase, and then are sequentially passed through the second purifier (7), the third purifier (11) and the fourth purifier (12) to remove impurities to obtain ultra-high purity hydrogen chloride gas; The third purifier (11) is provided with a polymer permeable membrane, and the fourth purifier (12) is filled with a metal cation exchange resin.

6. The device according to claim 5, characterized in that A first reflux pipe (61) is provided at the bottom of the first gas-liquid separator (6) and is connected to the top of the first distillation tower (4).

7. The device according to claim 5, characterized in that The invention also comprises a second distillation tower (8) for removing light components, a second condenser (9), and a second gas-liquid separator (10); the output end of the second purifier (7) is connected to the feed inlet of the second distillation tower (8), the top of the second distillation tower (8) is connected to the second condenser (9), the second condenser (9) is connected to the second gas-liquid separator (10), and the upper part of the second gas-liquid separator (10) is provided with a second crude product extraction pipe (101), and the lower part is provided with a second reflux pipe (102) and is connected to the top of the second distillation tower (8).

8. The device according to claim 5, characterized in that A first crude product extraction pipe (64) is also provided at the bottom of the first gas-liquid separator (6); and a third crude product extraction pipe (111) is provided at the third purifier (11).

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