Analysis method and analysis apparatus for hydrogen halide gas

Abstract

Provided is a method for analyzing a hydrogen halide gas that enables accurate measurement of the content of impurities in the hydrogen halide gas. A hydrogen halide gas is analyzed by an analysis apparatus to measure the content of impurities in the hydrogen halide gas. The analysis apparatus comprises: a hydrogen halide gas container (10); an analysis unit (20); a first flow path (30) that communicates the hydrogen halide gas container (10) with the analysis unit (20); and a second flow path (40) that branches from the first flow path (30). The analysis method comprises: a hydrogen halide gas pressure-accumulation purge step of performing pressure-accumulation purging in the first flow path (30) using the hydrogen halide gas; and an analysis step of continuing to supply the hydrogen halide gas in the hydrogen halide gas container (10) to the first flow path (30), and, while causing a portion of the hydrogen halide gas supplied to the first flow path (30) to flow to the second flow path (40), sending another portion of the hydrogen halide gas supplied to the first flow path (30) to the analysis unit (20) to analyze the hydrogen halide gas.

Description

Method and apparatus for analyzing hydrogen halide gas

[0001] The present disclosure relates to a method and an apparatus for analyzing hydrogen halide gas.

[0002] In order to accurately measure the content rate of impurities in hydrogen halide gas with an analyzer, it is necessary to prevent impurities from being mixed into the hydrogen halide gas to be analyzed during the analysis and the amount of impurities from increasing. During analysis, the hydrogen halide gas to be analyzed comes into contact with the members constituting the analyzer and the members (pipes, valves, etc.) for sending the hydrogen halide gas from the storage container (cylinder) of the hydrogen halide gas to the analyzer. However, since hydrogen halide is highly reactive, it may react with the contacted members to generate impurities. The above members that come into contact with the hydrogen halide gas may be formed of metal. When the metal forming the above members reacts with hydrogen halide, hydrogen gas is generated and mixed into the hydrogen halide gas to be analyzed as an impurity. For example, when a pipe made of stainless steel was used, the reaction with hydrogen halide was likely to occur.

[0003] Japanese Patent Publication Gazette No. 523629 of 2024

[0004] If a pipe formed of a metal material with high corrosion resistance is used, it is possible to suppress the reaction between hydrogen halide and the metal. However, for example, a pipe formed of Hastelloy (registered trademark), which is a metal material with high corrosion resistance, was expensive and not easily available. Also, even for a pipe formed of stainless steel, if the portion in contact with the hydrogen halide gas is subjected to an inactivation treatment, it is possible to suppress the reaction between hydrogen halide and the metal. An example of a stainless steel pipe subjected to an inactivation treatment is Altimetal (registered trademark), but it was also expensive like Hastelloy (registered trademark).

[0005] Thus, because impurities may be generated by the reaction between the hydrogen halide gas and the material in contact with it, it has not been easy to accurately measure the impurity content in the hydrogen halide gas using an analytical instrument. Furthermore, while it is possible to suppress the reaction between the hydrogen halide gas and the material in contact with it using special materials, these are expensive and not readily available. The object of this disclosure is to provide an analytical method and analytical instrument for hydrogen halide gas that can accurately measure the impurity content in the hydrogen halide gas.

[0006] To solve the aforementioned problems, one aspect of the present disclosure is as follows [1] to [9]. [1] An analytical method for measuring the content of impurities in a hydrogen halogen gas by analyzing the hydrogen halogen gas with an analytical device, wherein the analytical device comprises a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed, an analysis unit for analyzing the hydrogen halogen gas and detecting the impurities, a first flow path connecting the hydrogen halogen gas container and the analysis unit and sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit, and a second flow path branching off from the first flow path and sending the hydrogen halogen gas in the hydrogen halogen gas container to a part other than the analysis unit, and a hydrogen halogen gas purging step of performing a purging of the purged hydrogen halogen gas in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed, A method for analyzing hydrogen halogen gas, comprising: an analysis step in which, after performing the hydrogen halogen gas accumulating and purging step, the hydrogen halogen gas in the hydrogen halogen gas container is continuously supplied to the first channel, and a portion of the hydrogen halogen gas supplied to the first channel is flowed to the second channel, while the remaining portion of the hydrogen halogen gas supplied to the first channel is sent to the analysis unit to analyze the hydrogen halogen gas.

[0007] [2] The hydrogen halogen gas analysis method according to [1], wherein the hydrogen halogen gas purging step is repeated 10 or more times. [3] The hydrogen halogen gas analysis method according to [1] or [2], further comprising an inert gas purging step in which the purging of the first flow path is performed using an inert gas before the hydrogen halogen gas purging step.

[0008] [4] The method for analyzing hydrogen halogen gas according to any one of [1] to [3], wherein the first channel is made of stainless steel. [5] The method for analyzing hydrogen halogen gas according to any one of [1] to [4], wherein the impurity is hydrogen gas.

[0009] [6] An analytical apparatus for measuring the content of impurities in hydrogen halogen gas, comprising: a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed; an analysis unit for analyzing the hydrogen halogen gas and detecting the impurities; a first flow path connecting the hydrogen halogen gas container and the analysis unit and sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit; a hydrogen halogen gas pressure purging unit that performs pressure purging in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed; and a second flow path branching off from the first flow path and sending the hydrogen halogen gas in the hydrogen halogen gas container to a part other than the analysis unit.

[0010] [7] The hydrogen halogen gas analyzer according to [6], further comprising an inert gas pressure purging section that performs pressure purging in the first channel using an inert gas. [8] The hydrogen halogen gas analyzer according to [6] or [7], wherein the first channel is made of stainless steel. [9] The hydrogen halogen gas analyzer according to any one of [6] to [8], wherein the impurity is hydrogen gas.

[0011] According to this disclosure, the content of impurities in hydrogen halide gas can be accurately measured.

[0012] This figure illustrates an example of a hydrogen halogen gas analysis method and analytical apparatus according to this embodiment.

[0013] One embodiment of the present disclosure is described below. This embodiment is merely an example of the present disclosure, and the disclosure is not limited to this embodiment. Furthermore, various modifications or improvements can be made to this embodiment, and such modified or improved forms may also be included in the present disclosure.

[0014] The hydrogen halogen gas analysis method according to this embodiment is an analysis method for measuring the content of impurities in hydrogen halogen gas by analyzing hydrogen halogen gas with an analytical device, wherein the analytical device comprises a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed, an analysis unit for analyzing hydrogen halogen gas and detecting impurities, a first flow path connecting the hydrogen halogen gas container and the analysis unit and sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit, and a branch from the first flow path that sends the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit. The system includes a second channel for sending gas to the outside, and comprises a hydrogen halogen gas accumulating purging step which performs a purging of the accumulated pressure in the first channel using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed, and an analysis step which, after the hydrogen halogen gas accumulating purging step has been performed, continues to supply hydrogen halogen gas from the hydrogen halogen gas container to the first channel, while a portion of the hydrogen halogen gas supplied to the first channel flows to the second channel, and the remaining portion of the hydrogen halogen gas supplied to the first channel is sent to the analysis section to perform analysis of the hydrogen halogen gas.

[0015] The hydrogen halogen gas analyzer according to this embodiment is an analyzer for measuring the content of impurities in hydrogen halogen gas, and comprises: a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed; an analysis unit for analyzing the hydrogen halogen gas and detecting impurities; a first flow path connecting the hydrogen halogen gas container and the analysis unit and sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit; a hydrogen halogen gas pressure purging unit that performs pressure purging in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed; and a second flow path branching off from the first flow path and sending the hydrogen halogen gas in the hydrogen halogen gas container to a part other than the analysis unit.

[0016] According to the hydrogen halide gas analysis method and hydrogen halide gas analysis apparatus according to this embodiment, the content of impurities in the hydrogen halide gas can be accurately measured. Furthermore, according to the hydrogen halide gas analysis method and hydrogen halide gas analysis apparatus according to this embodiment, the content of impurities in the hydrogen halide gas can be accurately measured even when no special material is used to form the first channel that sends the hydrogen halide gas to be analyzed to the analysis unit. The hydrogen halide gas analysis method and analysis apparatus according to this embodiment will be described in detail below.

[0017] The hydrogen halogen gas analysis method according to this embodiment is an analysis method that measures the content of impurities in the hydrogen halogen gas by analyzing the hydrogen halogen gas with the hydrogen halogen gas analyzer according to this embodiment, and comprises a hydrogen halogen gas accumulator purging step and an analysis step.

[0018] [Hydrogen Halogen Gases to be Analyzed] The type of hydrogen halogen gas to be analyzed is not particularly limited; any of the following hydrogen halogens can be analyzed: hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI). Furthermore, a gas consisting of one type of hydrogen halogen gas may be analyzed, or a mixed gas of multiple types of hydrogen halogen gases may be analyzed. In addition, the type and concentration of impurities contained in the hydrogen halogen gas are not particularly limited; any type and concentration of impurities can be used for analysis.

[0019] [Hydrogen Halogen Gas Container] The configuration of the hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed is not particularly limited, but for example, a hydrogen halogen gas cylinder containing hydrogen halogen gas can be used as a hydrogen halogen gas container.

[0020] [Hydrogen Halogen Gas Pressure Purge Process] In the hydrogen halogen gas analysis method according to this embodiment, before the analysis process, a hydrogen halogen gas pressure purge process is performed, in which the pressure accumulated in the first flow path is purged using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed.

[0021] By performing a hydrogen halide gas purging process, deposits such as water adhering to the first channel can be removed from the first channel. Furthermore, by performing a hydrogen halide gas purging process, the material forming the inner surface of the first channel reacts with hydrogen halide to form a halide coating on the inner surface of the first channel, thereby inactivating the inner surface of the first channel. When the inner surface of the first channel is inactivated, the reaction between the material forming the first channel and hydrogen halide during the analysis process, which generates impurities, can be suppressed.

[0022] In the hydrogen halogen gas purging process, the number of times the purging of the purged gas in the first channel is performed using hydrogen halogen gas is not particularly limited; it may be repeated 10 or more times, 30 or more times, or 50 or more times. In other words, in the hydrogen halogen gas purging process, the purging may be repeated 10 or more times.

[0023] In the hydrogen halogen gas accumulator purging process, the hydrogen halogen gas used, i.e., the purging gas, shall be the same type of hydrogen halogen gas as the hydrogen halogen gas being analyzed. For example, if the hydrogen halogen gas being analyzed is hydrogen chloride gas, then the purging gas shall also be hydrogen chloride gas.

[0024] Similarly, the types of impurities present are also preferable; it is desirable that the types of impurities present in the hydrogen halogen gas being analyzed and the hydrogen halogen gas used for purging are the same. Furthermore, the same applies to the impurity content; it is preferable that the impurity content in the hydrogen halogen gas used for purging is less than or equal to the impurity content in the hydrogen halogen gas being analyzed. Therefore, the hydrogen halogen gas being analyzed may be used as the purging gas when performing the hydrogen halogen gas accumulating and purging process.

[0025] The pressure and temperature in the first flow path during the hydrogen halide gas accumulator purging process are not particularly limited, but the pressure may be less than atmospheric pressure, less than or equal to atmospheric pressure, at atmospheric pressure, greater than or equal to atmospheric pressure, or greater than atmospheric pressure. The temperature may be 0°C or higher, 20°C or higher, 30°C or higher, or 50°C or higher. The temperature may also be 100°C or lower, 50°C or lower, or 30°C or lower.

[0026] Accumulation purging refers to the operation of replacing the gas in a space with purge gas by supplying a purge gas into the space to be purged (the first flow path in this disclosure), accumulating the purge gas in that space, then discharging the gas in that space to the outside of the space, and then supplying purge gas into that space again.

[0027] Accumulator purging offers a higher purging effect and requires less purging gas than flow purging. Furthermore, accumulator purging is more effective at removing oxygen (O2) and hydrogen (H2) gases present in the dead space within the first flow path than flow purging. Flow purging, on the other hand, involves supplying purging gas into the space to be purged, thereby pushing out the stagnant gas in that space and replacing it with the purging gas.

[0028] [Hydrogen Halogen Gas Pressure Accumulation and Purge Section] The hydrogen halogen gas pressure accumulation and purge section of the hydrogen halogen gas analyzer according to this embodiment is not particularly limited in its configuration, as long as it is possible to supply hydrogen halogen gas to the first flow path and perform pressure purging in the first flow path. For example, the hydrogen halogen gas pressure accumulation and purge section can be configured using a hydrogen halogen gas container containing hydrogen halogen gas (for example, a hydrogen halogen gas cylinder containing hydrogen halogen gas).

[0029] [Analysis Process] In the hydrogen halogen gas analysis method according to this embodiment, the analysis process is performed after the hydrogen halogen gas accumulating and purging process. When performing the analysis process, the hydrogen halogen gas in the hydrogen halogen gas container is supplied to the first channel. The hydrogen halogen gas in the hydrogen halogen gas container is continuously supplied to the first channel, and a portion of the hydrogen halogen gas supplied to the first channel is continuously flowed to the second channel, while the remaining portion of the hydrogen halogen gas supplied to the first channel is sent to the analysis unit, where the hydrogen halogen gas is analyzed.

[0030] When analyzing hydrogen halide gas, if a portion of the hydrogen halide gas supplied to the first channel is not allowed to flow to the second channel, and the hydrogen halide gas supplied to the first channel remains in the first channel, a reaction between the material forming the first channel and the hydrogen halide will proceed, generating impurities. This may increase the impurity content of the hydrogen halide gas remaining in the first channel. As a result, it may be impossible to accurately measure the impurity content of the hydrogen halide gas.

[0031] In the hydrogen halide gas analysis method and apparatus according to this embodiment, during the analysis process, hydrogen halide gas from the hydrogen halide gas container is continuously supplied to the first channel, and a portion of the hydrogen halide gas supplied to the first channel is continuously flowed to the second channel. This prevents the hydrogen halide gas supplied to the first channel from remaining in the first channel. Therefore, the reaction between the material forming the first channel and the hydrogen halide is kept low, and impurities are less likely to be generated, thus preventing an increase in the impurity content of the hydrogen halide gas in the first channel.

[0032] In this way, since the hydrogen halide gas (the portion of the hydrogen halide gas supplied to the first channel) with low retention in the first channel is sent to the analysis section for analysis, the increase in the impurity content of the hydrogen halide gas in the first channel is suppressed, and the impurity content of the hydrogen halide gas can be accurately measured.

[0033] According to the hydrogen halide gas analysis method and apparatus of this embodiment, the reaction between the material forming the first channel and the hydrogen halide is kept to a low level, making it possible to use iron-based alloys such as stainless steel as the material forming the first channel and the material forming the valve. With the hydrogen halide gas analysis method and apparatus of this embodiment, even if iron-based alloy components such as stainless steel are used, analysis results comparable to those obtained when using components made of Hastelloy® or stainless steel components with an inert treatment applied to the surface can be obtained.

[0034] Therefore, the hydrogen halide gas analysis method and apparatus according to this embodiment can accurately analyze high-purity hydrogen halide gas with a low impurity content. For example, the impurity content of the hydrogen halide gas to be analyzed may be 50 ppm by volume or less, 10 ppm by volume or less, or 1 ppm by volume or less. In the analysis step, the hydrogen halide gas in the hydrogen halide gas container may be supplied to the first flow path continuously or intermittently.

[0035] Furthermore, in the analysis process, the flow rate of hydrogen halide gas sent to the analysis unit is not particularly limited, but for example, it may be 20 mL / min or more, 30 mL / min or more, 50 mL / min or more, 70 mL / min or more, 80 mL / min or more, or 100 mL / min or more. Furthermore, the flow rate of hydrogen halide gas sent to the analysis unit is not particularly limited, but for example, it may be 400 mL / min or less, 300 mL / min or less, 250 mL / min or less, or 200 mL / min or less. Furthermore, the flow rate of hydrogen halide gas sent to the analysis unit is not particularly limited, but for example, it may be 20 mL / min or more and 400 mL / min or less, 30 mL / min or more and 300 mL / min or less, 50 mL / min or more and 250 mL / min or less, or 70 mL / min or more and 200 mL / min or less.

[0036] Furthermore, in the analysis process, it is preferable that the flow rate of the hydrogen halogen gas flowing into the second channel is higher than the flow rate of the hydrogen halogen gas sent to the analysis unit. The flow rate of the hydrogen halogen gas flowing into the second channel varies depending on the type of material forming the first channel, the type of hydrogen halogen gas, temperature, pressure, etc., but for example, it may be 200 mL / min or more, 300 mL / min or more, or 400 mL / min or more. In addition, the flow rate of the hydrogen halogen gas flowing into the second channel may be 2000 mL / min or less, 1500 mL / min or less, 1000 mL / min or less, or 750 mL / min or less. Furthermore, the flow rate of the hydrogen halogen gas flowing into the second channel may be 200 mL / min or more and 2000 mL / min or less, 300 mL / min or more and 1500 mL / min or less, 400 mL / min or more and 1000 mL / min or less, or 400 mL / min or more and 750 mL / min or less.

[0037] If the material forming the first channel is stainless steel, the hydrogen halide is hydrogen chloride or hydrogen bromide, the temperature is 10°C or higher and 30°C or lower, and the pressure is atmospheric pressure or higher and 0.5 MPaG or lower, the flow rate of the hydrogen halide gas flowing into the second channel may be 200 mL / min or more and 2000 mL / min or less, 300 mL / min or more and 1500 mL / min or less, 400 mL / min or more and 1000 mL / min or less, or 400 mL / min or more and 750 mL / min or less.

[0038] Furthermore, the pressure and temperature in the first channel during the analysis process are not particularly limited, but the pressure may be less than atmospheric pressure, less than or equal to atmospheric pressure, at atmospheric pressure, greater than or equal to atmospheric pressure, or greater than atmospheric pressure. The temperature may be 0°C or higher, 20°C or higher, 30°C or higher, or 50°C or higher. The temperature may also be 100°C or lower, 50°C or lower, or 30°C or lower.

[0039] [Analysis Department] In the analysis department, there are no particular limitations on the type of measuring device used to detect impurities, but it is preferable to select a measuring device with high detection sensitivity depending on the type of impurity. Examples of measuring devices include gas chromatographs, mass spectrometers, gas chromatograph-mass spectrometers, infrared spectrophotometers, and ultraviolet-visible spectrophotometers.

[0040] The types of detectors used in gas chromatographs are not particularly limited, and examples include flame ionization detectors (FIDs), thermal conductivity detectors (TCDs), pulsed discharge photoionization detectors (PDDs), barrier discharge ionization detectors (BIDs), electron capture detectors (ECDs), and thermal ionization detectors (FTDs).

[0041] [First Flow Path] The first flow path may be formed of stainless steel. Examples of the type of stainless steel include SUS304, SUS316, etc. Also, a stainless steel pipe (for example, the Altimetal (registered trademark) tube manufactured by Agilent Technologies, Inc.) whose inner surface has been subjected to an inactivation treatment can be used as the first flow path. Furthermore, the first flow path may be formed of nickel (Ni), a nickel alloy, or resin.

[0042] [Second Flow Path] The type of material forming the second flow path is not particularly limited, and for example, it may be formed of stainless steel, nickel, a nickel alloy, or resin. The configuration on the downstream side of the second flow path is not particularly limited. That is, the hydrogen halide gas flowing into the second flow path may be sent to a detoxification device for detoxification treatment, absorbed in water to form a hydrohalic acid, sent to an exhaust gas tank for storage in the exhaust gas tank, or released to the outside air.

[0043] [Inert Gas Pressure Accumulation Purging Step] In the method for analyzing hydrogen halide gas according to the present embodiment, before the hydrogen halide gas pressure accumulation purging step, an inert gas pressure accumulation purging step of performing pressure accumulation purging in the first flow path using an inert gas may be further provided. By performing the inert gas pressure accumulation purging step, deposits and the like adhering to the inside of the first flow path can be removed from the first flow path, so that the amount of hydrogen halide gas used in the hydrogen halide gas pressure accumulation purging step can be reduced.

[0044] In the inert gas pressure accumulation purging step, the number of times of performing pressure accumulation purging in the first flow path using an inert gas is not particularly limited, and it may be repeated 10 times or more, 30 times or more, or 50 times or more. The type of inert gas is not particularly limited, and examples include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and nitrogen gas (N2).

[0045] The pressure and temperature in the first flow path during the implementation of the inert gas accumulation purge process are not particularly limited. The pressure may be less than atmospheric pressure, may be below atmospheric pressure, may be atmospheric pressure, may be above atmospheric pressure, or may exceed atmospheric pressure. Also, the temperature may be 0 °C or higher, may be 20 °C or higher, may be 30 °C or higher, or may be 50 °C or higher. Further, the temperature may be 100 °C or lower, may be 50 °C or lower, or may be 30 °C or lower.

[0046] [Inert gas accumulation purge section] The hydrogen halide gas analyzer according to the present embodiment may further include an inert gas accumulation purge section that performs accumulation purge in the first flow path using an inert gas. The configuration of the inert gas accumulation purge section is not particularly limited as long as it can supply an inert gas to the first flow path and perform accumulation purge in the first flow path. For example, an inert gas accumulation purge section can be configured using an inert gas container (e.g., an inert gas cylinder) in which an inert gas is stored.

[0047] [Impurities] Various impurities may be mixed into the hydrogen halide gas to be analyzed. There are impurities that have already been mixed into the hydrogen halide gas before analysis, and there are also impurities (impurities derived from the analyzer) that are mixed into the hydrogen halide gas from the analyzer during analysis.

[0048] For example, as impurities, there are impurities generated by the reaction of the material forming the first flow path with hydrogen halide, impurities mixed into the hydrogen halide gas due to the peeling of deposits adhering in the first flow path, and impurities mixed into the first flow path from the outside through a valve or the like provided in the first flow path.

[0049] If at least a portion of the first channel is formed of a material that can react with hydrogen halide, impurities may be generated by the reaction between the material forming the first channel and the hydrogen halide during analysis. Examples of impurities that may be generated by the reaction between the material forming the first channel and the hydrogen halide include the following: For example, if the material forming the first channel is a metal such as iron, steel, nickel, or nickel alloy, hydrogen gas may be generated. In other words, the impurity may be hydrogen gas. Also, if the material forming the first channel is a resin and the hydrogen halide is hydrogen fluoride, methane (CH4) may be generated. Furthermore, if the material forming the first channel is an oxide, water (H2O) may be generated.

[0050] Furthermore, examples of impurities that detach from deposits adhering to the first channel and mix with the hydrogen halide gas, and examples of impurities that enter the first channel from the outside via valves or the like provided in the first channel, include oxygen gas, nitrogen gas, air, carbon dioxide (CO2), water (H2O), resin, and oil.

[0051] The present disclosure will be further described below with reference to examples, comparative examples, and reference examples. The content of impurities in hydrogen halogen gas was measured using the hydrogen halogen gas analyzer shown in Figure 1. First, the hydrogen halogen gas analyzer shown in Figure 1 will be described. Figure 1 shows the state of the hydrogen halogen gas analyzer during the hydrogen halogen gas purging process.

[0052] The hydrogen halogen gas analyzer shown in Figure 1 comprises a hydrogen halogen gas container 10 containing the hydrogen halogen gas to be analyzed, an analysis unit 20 for analyzing the hydrogen halogen gas and detecting impurities in it, a first channel 30 connecting the hydrogen halogen gas container 10 and the analysis unit 20 and sending the hydrogen halogen gas from the container 10 to the analysis unit 20, a second channel 40 branching off from the first channel 30 and sending the hydrogen halogen gas from the container 10 to a part other than the analysis unit 20, and an inert gas container 50 containing an inert gas. The type of hydrogen halogen gas is either hydrogen chloride gas or hydrogen bromide gas.

[0053] The hydrogen halogen gas container 10 is a hydrogen halogen gas cylinder containing the hydrogen halogen gas to be analyzed. By opening and closing the valve 11 attached to the hydrogen halogen gas container 10, the hydrogen halogen gas contained in the hydrogen halogen gas container 10 can be supplied to or stopped from the first flow path 30.

[0054] Furthermore, the hydrogen halogen gas container 10 is also a hydrogen halogen gas cylinder containing hydrogen halogen gas, which is the purging gas used in the hydrogen halogen gas accumulating purging process. That is, this hydrogen halogen gas cylinder has both the function of "a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed" and the function of "a hydrogen halogen gas accumulating purging unit that performs purging of the accumulated pressure in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed," which are constituent elements of this disclosure. However, the hydrogen halogen gas cylinder containing the hydrogen halogen gas to be analyzed and the hydrogen halogen gas cylinder containing the purging gas used in the hydrogen halogen gas accumulating purging process may be separate cylinders.

[0055] The analysis unit 20 is a measuring device that analyzes hydrogen halide gas and detects impurities. It is a gas chromatograph (GC-PDD) that uses a pulsed discharge type photoionization detector (PDD) as its detector. The impurity to be detected is hydrogen gas. Inside the gas chromatograph, both Hastelloy® C22 piping and Ultimetal® tubing, which is stainless steel piping with an inertified inner surface, are used as the flow path for the hydrogen halide gas.

[0056] The first channel 30 is a pipe through which hydrogen halogen gas flows, and is made of stainless steel SUS316. The first channel 30 is equipped with a gate valve 31, a pressure reducing valve 32, and a gate valve 33 in order from the upstream side, and by opening and closing these valves, the flow of hydrogen halogen gas through the first channel 30 can be allowed or stopped. A temperature control device 35 and a thermocouple (not shown) are connected to the pressure reducing valve 32, and the temperature of the pressure reducing valve 32 can be adjusted by the temperature control device 35.

[0057] The hydrogen halogen gas analyzer shown in Figure 1 is equipped with a dry abatement device 80. The hydrogen halogen gas analyzed in the analysis unit 20 is sent to the dry abatement device 80, where it is subjected to abatement treatment before being locally exhausted. The second flow path 40 branches off from the section of the first flow path 30 between the gate valve 33 and the pressure reducing valve 32, and is a pipe that sends the hydrogen halogen gas that has flowed through the first flow path 30 to a section other than the analysis unit 20. In the hydrogen halogen gas analyzer shown in Figure 1, the second flow path 40 is a bypass flow path, allowing the hydrogen halogen gas that has flowed through the first flow path 30 to be sent to the dry abatement device 80 via the second flow path 40.

[0058] The second channel 40 is a piping made of stainless steel SUS316 through which hydrogen halogen gas flows. The second channel 40 is equipped with gate valves 41 and 42 in order from the upstream side, and by opening and closing these valves, the flow of hydrogen halogen gas through the second channel 40 can be allowed or stopped.

[0059] Furthermore, by opening the gate valve 33 and closing the gate valves 41 and 42, all of the hydrogen halogen gas in the first channel 30 can be sent to the analysis unit 20. Also, by closing the gate valve 33 and opening the gate valves 41 and 42, all of the hydrogen halogen gas in the first channel 30 can be sent to the second channel 40. Moreover, by opening the gate valves 33, 41 and 42, a portion of the hydrogen halogen gas in the first channel 30 can be sent to the second channel 40 while the rest of the hydrogen halogen gas in the first channel 30 is sent to the analysis unit 20.

[0060] The inert gas container 50 is an inert gas cylinder containing inert gas. By opening and closing a valve 51 attached to the inert gas container 50, the inert gas contained in the inert gas container 50 can be supplied to or stopped from the inert gas flow path 53. The inert gas flow path 53 is connected to the first flow path 30. That is, since the inert gas container 50 and the first flow path 30 are connected by the inert gas flow path 53, it is possible to supply the inert gas in the inert gas container 50 to the first flow path 30 via the inert gas flow path 53. The type of inert gas is helium.

[0061] The inert gas passage 53 is a pipe made of stainless steel SUS316 through which the inert gas flows. The inert gas passage 53 is equipped with gate valves 54 and 55 in order from the upstream side, and by opening and closing these valves, the flow of the inert gas through the inert gas passage 53 can be allowed or stopped.

[0062] The inert gas pressure purging section is comprised of an inert gas container 50, an inert gas flow path 53, a gate valve 54, and a gate valve 55, etc. The inert gas pressure purging section allows for the execution of an inert gas pressure purging process, which involves purging the accumulated pressure in the first flow path 30 using an inert gas.

[0063] An exhaust passage 61 is connected to the portion of the second passage 40 between the gate valves 41 and 42. The exhaust passage 61 is equipped with a gate valve 63 and a vacuum pump 62, in order from the upstream side. By using the exhaust passage 61, gate valves 63 and vacuum pump 62, it is possible to discharge the gas present in the first passage 30 to the outside of the hydrogen halogen gas analyzer shown in Figure 1.

[0064] The hydrogen halide gas analyzer shown in Figure 1 is further equipped with a heating device (not shown) that heats the piping to prevent the liquefaction of hydrogen halides. In Figure 1, the shaded area represents the heating region 70 heated by the heating device. As can be seen from Figure 1, a portion of the first channel 30 and a portion of the second channel 40 can be heated by the heating device. The temperature of the heating region 70 is not particularly limited as long as it prevents the liquefaction of hydrogen halides, but in this embodiment, comparative example, and reference example, the heating region 70 is heated to 50°C.

[0065] Figure 1 shows symbols for various valves. When a valve symbol is displayed in white, it indicates that the valve is open, and when a valve symbol is displayed in black, it indicates that the valve is closed. Therefore, Figure 1 shows the open and closed states of various valves when the hydrogen halogen gas accumulator purging process is being carried out.

[0066] [Reference Example 1] Hydrogen halide gas was analyzed using the hydrogen halide gas analyzer shown in Figure 1. The temperature of the first channel 30 and the second channel 40 was room temperature except for the heated area 70. First, an inert gas purging process was performed. Specifically, gate valves 54, 55, 31, 41 and pressure reducing valve 32 were opened, gate valves 33, 42, and 63 were closed, and valve 51 of the inert gas container 50 was opened. Helium was supplied to the first channel 30 via the inert gas channel 53 until the pressure in the first channel 30 reached 0.5 MPaG. Then, gate valve 55 was switched to the closed state and gate valve 63 was switched to the open state, and the vacuum pump 62 was operated to discharge the helium in the first channel 30. This operation (purging) of supplying helium to the first channel 30 and then discharging the helium in the first channel 30 was repeated 30 times.

[0067] Next, a hydrogen halogen gas purging process was performed. Specifically, gate valves 31, 41 and pressure reducing valve 32 were opened, gate valves 55, 33, 42, and 63 were closed, and valve 11 of the hydrogen halogen gas container 10 was opened. Hydrogen chloride gas was supplied to the first channel 30 until the pressure in the first channel 30 reached 0.5 MPaG. Then, valve 11 was switched to the closed position, gate valve 63 was switched to the open position, and the vacuum pump 62 was operated to discharge the hydrogen chloride gas from the first channel 30. This operation (purging), in which hydrogen chloride gas is supplied to the first channel 30 and then discharged, was repeated 10 times.

[0068] Next, the gate valves 31, 41 and pressure reducing valve 32 were opened, and the gate valves 55, 33, 42, and 63 were closed. Then, the valve 11 of the hydrogen halogen gas container 10 was opened, and hydrogen chloride gas was supplied to the first flow path 30 until the pressure in the first flow path 30 reached 0.5 MPaG.

[0069] Next, the gate valve 33 was switched to the open position, and the hydrogen chloride gas in the first flow path 30 was sent to the analysis unit 20, where the hydrogen gas content in the hydrogen chloride gas was measured. The hydrogen gas content was measured intermittently multiple times, and once the value stabilized (when the coefficient of variation of the results of three consecutive measurements became 10% or less), that value was used as the analysis result. As a result, the hydrogen gas content in the hydrogen chloride gas was 13.9 ppm by volume.

[0070] The measurement conditions for gas chromatography in the analysis unit 20 are as follows: • Gas chromatograph: Agilent 8890 GC-PHID manufactured by Agilent Technologies • Column type: G3591-81035 manufactured by Agilent Technologies • Column temperature: 40°C • Carrier gas type: Helium • Carrier gas pressure: 42.5 psi • Sample injection volume: 2 mL

[0071] Next, the gate valve 33 was switched to the closed position, and hydrogen chloride gas was supplied to the first channel 30 until the pressure in the first channel 30 reached 3 MPaG. After leaving it in that state for 30 minutes, the gate valve 33 was switched to the open position, and the hydrogen chloride gas in the first channel 30 was sent to the analysis unit 20, where the hydrogen gas content in the hydrogen chloride gas was measured in the same manner as above. As a result, the hydrogen gas content in the hydrogen chloride gas was 47.8 volume ppm.

[0072] Specifically, by filling the first channel 30 with hydrogen chloride gas and leaving it for 30 minutes, the hydrogen gas content in the hydrogen chloride gas within the first channel 30 increased significantly. From this result, it was confirmed that the stainless steel forming the first channel reacted with the hydrogen chloride within the first channel to generate hydrogen gas, which is an impurity.

[0073] [Reference Example 2] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Reference Example 1, except that hydrogen chloride gas was replaced with hydrogen bromide gas. As a result, the hydrogen gas content in the hydrogen bromide gas before standing for 30 minutes was 36.5 volume ppm, and the hydrogen gas content in the hydrogen bromide gas after standing for 30 minutes was 106.8 volume ppm.

[0074] Specifically, by filling the first channel 30 with hydrogen bromide gas and leaving it for 30 minutes, the hydrogen gas content in the hydrogen bromide gas within the first channel 30 increased significantly. From this result, it was confirmed that the stainless steel forming the first channel reacted with the hydrogen bromide within the first channel to generate hydrogen gas, which is an impurity.

[0075] [Example 1] Hydrogen halide gas was analyzed using the hydrogen halide gas analyzer shown in Figure 1. The temperatures of the first channel 30 and the second channel 40 were at room temperature except for the heated region 70. First, the inert gas accumulator purging process and the hydrogen halide gas accumulator purging process were carried out in the same manner as in Reference Example 1.

[0076] Next, the analysis process was carried out. Specifically, gate valves 31, 41, 42 and pressure reducing valve 32 were opened, and gate valves 55, 33, 63 were closed. Then, valve 11 of the hydrogen halogen gas container 10 was opened, and hydrogen chloride gas was supplied to the first flow path 30. Since gate valve 33 was closed and gate valves 41 and 42 were open, the hydrogen chloride gas supplied from the hydrogen halogen gas container 10 to the first flow path 30 flowed into the second flow path 40 and was discharged to the dry abatement device 80 via the second flow path 40. The flow rate of hydrogen chloride gas supplied from the hydrogen halogen gas container 10 to the first flow path 30 was set to 170 mL / min. In addition, the flow rate of hydrogen chloride gas was adjusted using gate valve 42, and the flow rate of hydrogen chloride gas flowing through the second flow path 40 was set to 500 mL / min.

[0077] While continuously supplying hydrogen chloride gas from the hydrogen halogen gas container 10 to the first channel 30, the gate valve 33 was intermittently opened to intermittently send the hydrogen chloride gas in the first channel 30 to the analysis unit 20, and multiple analyses were performed intermittently. Specifically, hydrogen chloride gas from the hydrogen halogen gas container 10 was continuously supplied to the first channel 30, and a portion of the hydrogen chloride gas supplied to the first channel 30 was flowed to the second channel 40, while the remaining portion of the hydrogen chloride gas supplied to the first channel 30 was sent to the analysis unit 20, and the hydrogen gas content in the hydrogen chloride gas was measured. The flow rate of hydrogen chloride gas sent to the analysis unit 20 was set to 170 mL / min.

[0078] The hydrogen gas content was measured intermittently multiple times as described above. Once the content value stabilized (when the coefficient of variation of three consecutive measurement results was 10% or less), that value was used as the analysis result. As a result, the hydrogen gas content in the hydrogen chloride gas was 6.1 ppm by volume. The results are shown in Table 1.

[0079]

[0080] [Comparative Example 1] Hydrogen halide gas was analyzed using the hydrogen halide gas analyzer shown in Figure 1. The temperatures of the first channel 30 and the second channel 40 were at room temperature except for the heated region 70. First, the inert gas accumulator purging process and the hydrogen halide gas accumulator purging process were carried out in the same manner as in Reference Example 1.

[0081] Next, the analysis process was carried out. Specifically, the gate valve 33 was switched to the open position, and the hydrogen chloride gas in the first channel 30 was sent to the analysis unit 20, where the hydrogen gas content in the hydrogen chloride gas was measured. Since the gate valves 41 and 42 remained closed, the hydrogen chloride gas in the first channel 30 did not flow into the second channel 40. The hydrogen gas content was measured intermittently multiple times, and once the value stabilized (when the coefficient of variation of the results of three consecutive measurements became 10% or less), that value was used as the analysis result. As a result, the hydrogen gas content in the hydrogen chloride gas was 13.2 volume ppm. The results are shown in Table 1.

[0082] Comparing the measurement results of Example 1 and Comparative Example 1, it can be seen that, according to the hydrogen halide gas analysis method and analytical apparatus of this disclosure, the impurity content in the hydrogen halide gas can be accurately measured even without using special materials such as Hastelloy® as the material for forming the first channel 30.

[0083] [Example 2] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Example 1, except that the hydrogen halogen gas purging process was repeated 30 times. As a result, the hydrogen gas content in the hydrogen chloride gas was 0.8 ppm by volume. The results are shown in Table 1.

[0084] [Comparative Example 2] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Comparative Example 1, except that the hydrogen halogen gas purging process was repeated 30 times. As a result, the hydrogen gas content in the hydrogen chloride gas was 1.8 ppm by volume. The results are shown in Table 1.

[0085] Comparing the measurement results of Example 2 and Comparative Example 2, it can be seen that, according to the hydrogen halide gas analysis method and analytical apparatus of this disclosure, the impurity content in the hydrogen halide gas can be accurately measured even without using special materials such as Hastelloy® as the material for forming the first channel 30.

[0086] [Example 3] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Example 1, except that hydrogen bromide gas was used as the hydrogen halogen gas. As a result, the hydrogen gas content in the hydrogen bromide gas was 19.1 ppm by volume. The results are shown in Table 1.

[0087] [Comparative Example 3] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Comparative Example 1, except that hydrogen bromide gas was used as the hydrogen halogen gas. As a result, the hydrogen gas content in the hydrogen bromide gas was 38.4 ppm by volume. The results are shown in Table 1.

[0088] Comparing the measurement results of Example 3 and Comparative Example 3, it can be seen that, according to the hydrogen halide gas analysis method and analytical apparatus of this disclosure, the impurity content in the hydrogen halide gas can be accurately measured even without using special materials such as Hastelloy® as the material for forming the first channel 30.

[0089] [Example 4] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Example 2, except that hydrogen bromide gas was used as the hydrogen halogen gas. As a result, the hydrogen gas content in the hydrogen bromide gas was 4.7 ppm by volume. The results are shown in Table 1.

[0090] [Comparative Example 4] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Comparative Example 2, except that hydrogen bromide gas was used as the hydrogen halogen gas. As a result, the hydrogen gas content in the hydrogen bromide gas was 28.6 ppm by volume. The results are shown in Table 1.

[0091] Comparing the measurement results of Example 4 and Comparative Example 4, it can be seen that, according to the hydrogen halide gas analysis method and analytical apparatus of this disclosure, the impurity content in the hydrogen halide gas can be accurately measured even without using special materials such as Hastelloy® as the material for forming the first channel 30.

[0092] [Example 5] The hydrogen gas content in the hydrogen halogen gas was measured in the same manner as in Example 4, except that the first channel 30 was made of Hastelloy® C22 piping and the hydrogen bromide gas cylinder used was different from that used in Examples 3 and 4 and Comparative Examples 3 and 4. In other words, the hydrogen gas content in the hydrogen bromide gas used in Example 5 was different from that used in Examples 3 and 4 and Comparative Examples 3 and 4. As a result, the hydrogen gas content in the hydrogen bromide gas was 0.4 ppm by volume. The results are shown in Table 1.

[0093] [Example 6] A control experiment was conducted in accordance with Example 5. Specifically, the hydrogen gas content in the hydrogen halide gas was measured in the same manner as in Example 5, except that the first flow path 30 was a pipe made of stainless steel SUS316. As a result, the hydrogen gas content in the hydrogen bromide gas was 0.3 volume ppm. The results are shown in Table 1.

[0094] Comparing the measurement results of Example 5 and Example 6, it can be seen that, according to the hydrogen halide gas analysis method and analytical apparatus of this disclosure, even when stainless steel is used as the material for forming the first channel 30, the impurity content in the hydrogen halide gas can be measured to the same extent as when Hastelloy® is used as the material for forming the first channel 30.

[0095] 10...Hydrogen halide gas container 20...Analysis section 30...First flow path 40...Second flow path 50...Inert gas container 53...Inert gas flow path 70...Heating area

Claims

1. An analytical method for measuring the content of impurities in a hydrogen halogen gas by analyzing the hydrogen halogen gas with an analytical device, wherein the analytical device comprises a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed, an analysis unit for analyzing the hydrogen halogen gas and detecting the impurities, a first flow path connecting the hydrogen halogen gas container and the analysis unit and sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit, and a second flow path branching off from the first flow path and sending the hydrogen halogen gas in the hydrogen halogen gas container to a part other than the analysis unit, and a hydrogen halogen gas purging step of performing a purging of the purged hydrogen halogen gas in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed, A method for analyzing hydrogen halogen gas, comprising: an analysis step in which, after performing the hydrogen halogen gas accumulating and purging step, the hydrogen halogen gas in the hydrogen halogen gas container is continuously supplied to the first channel, and a portion of the hydrogen halogen gas supplied to the first channel is flowed to the second channel, while the remaining portion of the hydrogen halogen gas supplied to the first channel is sent to the analysis unit to analyze the hydrogen halogen gas.

2. The method for analyzing hydrogen halogen gas according to claim 1, wherein the hydrogen halogen gas accumulating purging step is repeated 10 or more times.

3. The method for analyzing hydrogen halogen gas according to claim 1 or claim 2, further comprising an inert gas pressure purging step, in which the pressure in the first flow path is purged using an inert gas, prior to the hydrogen halogen gas pressure purging step.

4. The method for analyzing hydrogen halide gas according to claim 1 or claim 2, wherein the first channel is formed of stainless steel.

5. The method for analyzing hydrogen halide gas according to claim 1 or claim 2, wherein the impurity is hydrogen gas.

6. An analytical apparatus for measuring the content of impurities in hydrogen halogen gas, comprising: a hydrogen halogen gas container containing the hydrogen halogen gas to be analyzed; an analysis unit for analyzing the hydrogen halogen gas and detecting the impurities; a first flow path connecting the hydrogen halogen gas container and the analysis unit, and for sending the hydrogen halogen gas in the hydrogen halogen gas container to the analysis unit; a hydrogen halogen gas pressure purging unit for performing pressure purging in the first flow path using the same type of hydrogen halogen gas as the hydrogen halogen gas to be analyzed; and a second flow path branching off from the first flow path and sending the hydrogen halogen gas in the hydrogen halogen gas container to a part other than the analysis unit.

7. The hydrogen halogen gas analyzer according to claim 6, further comprising an inert gas pressure purging unit that performs pressure purging in the first flow path using an inert gas.

8. The hydrogen halide gas analyzer according to claim 6 or claim 7, wherein the first channel is formed of stainless steel.

9. The hydrogen halide gas analyzer according to claim 6 or claim 7, wherein the impurity is hydrogen gas.

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