JP3896464B2 - Gas separation and concentration equipment - Google Patents

Description

  The present invention relates to a gas separation / concentration device, and in particular, as a pre-stage for detecting and analyzing gas molecules or gas isotope molecules by a gas chromatograph analysis device, gas molecules to be analyzed contained in a sample gas, etc. The present invention relates to a gas separation and concentration device for separation and concentration.

  Conventionally, a trace amount of gas molecules (for example, hydrogen molecules) or gas isotope molecules (for example, light hydrogen molecules, deuterium molecules, and tritium molecules) contained in the atmosphere are detected and subjected to concentration analysis. Has been done. In particular, in recent years, in various industries including the semiconductor industry and in fusion-related facilities that monitor the abundance ratio of radioactive isotopes in the atmosphere, sophistication of technology for detecting trace amounts of gas molecules and gas isotope molecules Is required. Therefore, the analysis accuracy required for conventional analyzers, etc., is in ppm units, but now it is required to analyze gas molecules with accuracy of ppb units and in special fields in ppt units. There is.

  Here, gas chromatograph analyzers are known as detectors (analyzers) that detect minute amounts of gas molecules and the like and quantitatively and qualitatively perform concentration analysis and component analysis. This gas chromatograph analyzer has, as its configuration, a carrier gas for sending a sample gas to be analyzed, a gas control unit for controlling the gas flow rate of the carrier gas, and a sample gas introduction unit for introducing the sample gas The difference between the column connected to the sample gas inlet and heated to a predetermined temperature and the time required for the sample gas introduced into the column to be discharged from the column outlet (retention time: retention time) And a detector for detecting the sample gas separated into the respective components. Furthermore, the inventors of the present invention can combine these gas chromatograph analyzers with an atomic absorption device capable of analyzing highly sensitive metal elements, etc., and measure the concentration of trace amounts of hydrogen molecules. A hydrogen analyzer has been developed (see Non-Patent Document 1, for example).

Takao Kawano et al, Jpn. Journal of Applied Physics, 2003, Vol.42, p549

  When a minute amount of gas molecules or the like is detected and concentration analysis or component analysis is performed, a process for removing impurities or the like that may impair analysis accuracy in advance may be performed before analysis with a gas chromatograph analyzer. Furthermore, in order to increase the analysis accuracy so that gas molecules, etc. that are contained in the sample gas in a trace amount can be detected with high sensitivity, the sample gas to be analyzed by the gas chromatograph analyzer is concentrated to a high concentration. There is. In this case, as a conventional concentration treatment method, an existing concentration tube is used for concentration.

  However, in the concentration process using such a concentration tube, the processing amount per one time is limited, and it may take a long processing time to concentrate the amount of gas molecules and the like necessary for the analysis. Furthermore, there is a high possibility that impurities are mixed in the concentrated gas molecules and the analysis gas is contaminated. As a result, the accuracy may be lowered by the concentration process. Furthermore, in conventional separation and concentration treatment, gas isotope molecules including hydrogen isotope molecules such as light hydrogen molecules, deuterium molecules, and tritium molecules are separated and concentrated to measure each isotope molecule. It was difficult to do. In particular, it is known that the ratio of deuterium molecules and tritium molecules naturally present in the atmosphere or the like is extremely low, and it has been necessary to perform high-sensitivity detection with a detector by performing a concentration treatment. Here, in the case of hydrogen molecules, it is known that six types of hydrogen isotope molecules are formed by the combination of two hydrogen atoms constituting the hydrogen molecule. It was required to accurately perform the ratio and the like.

  Therefore, in view of the above circumstances, the present invention provides a gas separation and concentration apparatus capable of easily separating and concentrating gas molecules and the like in order to detect and analyze trace amounts of gas molecules and gas isotope molecules with high sensitivity. The issue is to provide

In order to solve the above-described problems, the gas separation and concentration apparatus of the present invention is connected to the sample gas introduction unit for introducing a sample gas containing gas molecules to be analyzed by a preset amount, and the sample gas introduction unit. A gas separation column unit that separates the gas molecules from the sample gas introduced by a set amount by using a difference in holding time required to pass through the separation column; and a column outlet of the separation column of the gas separation column unit The gas molecules separated and flowed to the gas flow path, and separated into the gas separation column connected to the gas discharge port the separation gas from which the gas molecules were separated from the sample gas in the gas separation column section, respectively. A flow path switching unit that switches the flow based on a difference in holding time required to pass through the separation column, and is connected to the flow path switching unit and the gas flow path, and is again connected to the separation column. Circulation flow path for deriving the gas molecules to the sample gas introduction portion for the passage of the gas molecules is flowed analysis passage density is increased, and separation of gaseous isotopes molecules to be analyzed from the gas molecules In order to perform the processing to be performed, each of the concentrated gas flow paths connected to the gas molecule introduction section for introducing the gas molecules can be switched to flow, and the circulation flow path, the analysis flow path, and the concentrated gas flow path The gas molecules that are switched and flowed from the flow path switching unit by the difference in holding time by the sample gas introduced by a set amount are temporarily stored in the space of the gas flow path. And concentrating the gas molecules, increasing the concentration of the gas molecules, and concentrating the gas molecules, and connecting the concentration unit and the concentrated gas flow path, the gas molecules being set in advance by a predetermined amount. Using the difference in retention time required to pass the gas isotope molecules from the gas molecules introduced into the gas molecule introduction unit and the gas molecule introduction unit, which are connected to the gas molecule introduction unit and set by a set amount. An isotope separation column part to be separated; and a second column outlet of the isotope separation column part of the isotope separation column part; Switching the residual gas from which the gas isotope molecules have been separated from the gas molecules in the separation column section to the residual gas flow path connected to the gas discharge port based on the difference in holding time required for passing through the isotope separation column, respectively. Isotope flow channel switching section, connected to the isotope flow channel switching section via the isotope flow channel, to the gas molecule introduction section to pass the gas molecules again through the isotope separation column Derivation Each of the isotope circulation channels and the isotope analysis channels through which the gas isotope molecules flow, and the respective isotope circulation channels and the isotope analysis channels. The gas isotope molecules that are switched by the gas molecules introduced by the set amount by the difference in holding time are temporarily flown in the space of the isotope channels. And an isotope concentrating section for increasing the concentration of the gas isotope molecules and concentrating the gas isotope molecules.

  Here, examples of gas molecules to be analyzed include gases such as hydrogen, nitrogen, oxygen, carbon dioxide, and hydrocarbons. In addition, the gas separation column section is configured with a separation column through which the sample gas can flow, and can be formed by diverting a column used in an existing gas chromatograph analyzer. It is. The separation column of the gas separation column section is, for example, heated to a predetermined temperature in advance for separation of the sample gas, and the sample gas is separated into each component by flowing inside the separation column. It is discharged at different holding times required for passing through the separation column from the outlet.

  Furthermore, the flow path switching unit refers to the flow path through which the separation gas from which the gas molecules have been removed from the gas molecules to be analyzed and the sample gas discharged from the column outlet of the separation column, respectively, due to the difference in retention time. To switch. That is, the gas molecules are switched by measuring the holding time so that they flow to the gas flow path for subsequent analysis and the like, while the separation gas flows through the separation gas flow path connected to the gas discharge port. And is discharged to the outside as it is. Here, as a general tendency, it is known that a gas molecule such as a hydrogen molecule having a small molecular weight has a short retention time, while a molecule having a large molecular weight has a long retention time. Therefore, for example, when hydrogen molecules are to be separated, immediately after the sample gas is sent from the sample gas introduction section to the separation column, the hydrogen molecules discharged from the column outlet in a short holding time flow through the gas flow path. The flow path switching unit is switched, and after a predetermined time has elapsed, a switching process is performed so that a separation gas having a long retention time in which gas molecules are separated from the sample gas flows through the separation gas flow path. As a result, only hydrogen molecules can selectively flow through the gas flow path. The configuration of the flow path switching unit is not particularly mentioned, but examples include one in which one or a plurality of valves are connected to the respective flow paths and the flow paths are switched by opening and closing each valve. In addition, the switching operation of the flow path switching unit may be either when the switching timing is set in advance based on the difference in the holding time and automatically switched by a timer or the like, or manually switched by the operator. .

In addition, the concentration section is separated through the gas separation column section, and further the gas molecules selectively separated by the flow path switching section are connected to a detector for analyzing the concentration, etc., And, in order to improve the analysis accuracy, the gas molecules are again switched to flow through circulation channels for concentrating by passing gas molecules again through the gas separation column section. Here, the circulation channel is connected to a sample gas introduction part into which the sample gas is first introduced. Therefore, when gas molecules are switched to flow through the circulation channel by the concentrating unit, the gas molecules are again introduced into the sample gas introduction unit and undergo the same separation treatment as the sample gas introduced first. It becomes. On the other hand, the gas molecules switched to flow in the analysis flow path are analyzed by a detector or the like through subsequent processing.

  Therefore, according to the gas molecule concentrator of the present invention, the sample gas containing the gas molecule or gas isotope molecule to be analyzed is introduced into the sample gas introduction part together with the carrier gas such as helium gas for sending the sample gas. be introduced. And sample gas is sent out so that the inside of the separation column of a gas separation column part may flow from a sample gas introduction part. Thereby, by flowing through the inside of the separation column heated to a predetermined temperature, the sample gas is separated for each gas molecule (gas component), and is discharged from the column outlet according to each holding time. At this time, the flow path switching unit installed at the column outlet discharges the flow path through which the gas molecules (for example, hydrogen molecules) to be analyzed and other gases (separation gas) flow from the column outlet. Each can be switched using the difference in holding time.

Thereby, the gas molecule to be analyzed selectively flows in the gas channel and is stored in the space of the gas channel . Here, the sample gas is sent to the above-described sample gas introduction unit by a predetermined amount, that is, by a “batch method”. For this reason, each time a sample gas is introduced, the separated gas molecules are delivered to the space of the gas flow path, and are gradually accumulated and stored. As a result, by introducing the sample gas a plurality of times, the gas channel space between the concentrating unit and the channel switching unit is in a state in which the concentration (density) of gas molecules is high. At this time, in order to obtain concentrated gas molecules, it is necessary to separate the sample gas multiple times as described above. Therefore, there is a high possibility that the gas molecules stored in the space of the gas channel are mixed with other gas molecules whose retention time approximates to the gas molecules. As a result, there is a possibility that the accuracy of analysis by a detector described later is lowered.

Therefore, the gas separation and concentration apparatus of the present invention is connected to a circulation flow path in which gas molecules concentrated at a high concentration in the space of the gas flow path by a batch method are connected so as to communicate between the concentration section and the sample gas introduction section. The gas molecules that have been sent out and have reached the use gas introduction section can pass through the separation column of the gas separation column section again. Then, after repeating the separation and concentration process of gas molecules by the batch method described above and the circulation process using the circulation channel a plurality of times, it is sent to the analysis channel connected to the detector from the concentration unit to increase the concentration. Only gas molecules that are concentrated and have few impurities can be detected and analyzed by the detector. In particular, it is possible to easily concentrate the gas molecules to be analyzed contained in the sample gas by adopting a batch method in which the sample gas is introduced into the separation column by a predetermined set amount and separated. .

  Here, the gas isotope molecule is a gas molecule containing isotope atoms having different neutron numbers. More specifically, in the case of hydrogen, the isotopes of deuterium and triple are compared with light hydrogen. Hydrogen is present. And hydrogen molecules composed of two hydrogen atoms per molecule, the combination of these isotopes, "light hydrogen-light hydrogen", "light hydrogen-deuterium", "light hydrogen-tritium", There are six types of hydrogen isotope molecules, “deuterium-deuterium”, “deuterium-tritium”, and “tritium-tritium”.

  Therefore, according to the gas separation and concentration apparatus of the present invention, the gas molecules introduced into the concentrated gas flow path through the separation and concentration cycle performed by the gas separation column unit and the concentration unit described above, etc. by the gas molecule introduction unit, A predetermined set amount is introduced into the isotope separation column. When the analysis target is a hydrogen molecule, it is known that the isotope separation column can be separated into each isotope component by cooling to an extremely low temperature state. For example, minus 196 ° C. using liquid nitrogen as a coolant. It is cooled to a very low temperature up to the vicinity. As described above, the condensed gas molecules pass through the cooled conductor separation column, thereby cooling the impurities contained in the gas molecules, and solidifying the gas molecules (substance) having a melting point higher than the above-described minus 196 ° C. The second column outlet of the cooling column cannot be reached. That is, other gas components are collected in the isotope separation column, and impurities can be removed.

  Furthermore, it is known that a plurality of gas isotope molecules contained in the gas molecule have different retention times required for passing through the isotope separation column by cooling the gas molecule to a cryogenic temperature. Thus, only the gas isotope molecule to be analyzed is selectively passed through the isotope channel based on the difference in holding time by the isotope channel switching unit installed at the second column outlet of the cooling column. Residual gas containing gas isotope molecules other than can flow into the residual gas flow path. The gas isotope molecules separated and selectively flown into the isotope channel are connected to the isotope enrichment section. Furthermore, the isotope enrichment section is connected to an isotope circulation channel that communicates between the gas molecule introduction sections.

Here, since the gas molecule introduction unit, the isotope channel switching unit, and the isotope enrichment unit have substantially the same functions as the sample gas introduction unit, the channel switching unit, and the enrichment unit, detailed description is omitted here. To do. As a result, gas molecules are introduced into the cooling column of the isotope separation column unit by a set amount, and only the gas isotope molecules to be analyzed are selectively flowed to the isotope channel by the isotope channel switching unit. It is stored in the body channel space . Furthermore, by repeating the cycle of “gas molecule introduction part → isotope separation column part → isotope flow path switching part → isotope enrichment part”, gas isotope molecules are separated and enriched by the same process as the gas molecules described above. can do. After that, the concentrated gas isotope molecules are sent to a detector connected to the isotope analysis flow path, so that the gas isotope molecules (for example, “tritium-tritium” gas isotope molecules, etc.) are highly sensitive. ) Can be detected and analyzed. The detailed operation is the same as the gas molecule separation and concentration process already described, and thus the description thereof is omitted here. The cooling temperature of the cooling column can be set as appropriate in accordance with the properties of the gas isotope molecules to be separated, and the coolant used at that time may be other than liquid nitrogen. .

Furthermore, in addition to the above configuration, the gas separation and concentration apparatus according to the present invention includes the “the final separation unit is connected to the concentration unit via the analysis channel, and the concentration is increased in the space of the gas channel. It may have a pre-analytical gas separation column section that separates gas molecules using the difference in retention time required for passage through the component separation column.

  Therefore, according to the gas separation and concentration apparatus of the present invention, the concentrated gas molecules are subjected to final component separation in the pre-analysis gas separation column before analysis, and then separated and other gas molecules. Detection and analysis. Thereby, the analysis accuracy of gas molecules can be further improved by performing the final component separation immediately before the analysis. Here, as the pre-analysis gas separation column part and the component separation column, those of the same type used in the above-described separation and concentration of gas molecules can be used.

Further, the gas separation / concentration apparatus of the present invention has the above-described structure, in which “the final separation unit is connected to the isotope enrichment unit via the isotope analysis channel, and the concentration in the space of the isotope channel is set. It may further comprise a pre-analytical isotope separation column section that separates the gas isotope molecules having an increased valence by utilizing the difference in retention time required for passage through the isotope component separation column.

  Therefore, according to the gas separation and concentration apparatus of the present invention, the gas isotope molecules concentrated by the isotope enrichment section are finally subjected to isotope separation by the isotope component separation column of the pre-analysis isotope separation column section and separated. Each gas isotope molecule is analyzed. Thereby, the analysis accuracy of gas isotope molecules can be further improved by performing the final isotope separation immediately before the analysis. Here, as the pre-analysis isotope separation column section and the isotope component separation column, those having the same configuration used for the separation and concentration of the above-mentioned gas isotope molecules can be used.

As described above, as an effect of the present invention, gas molecules or gas isotope molecules are detected and analyzed from the column according to the difference in retention time using the analysis principle of the gas chromatograph analyzer as a pre-stage treatment. The gas molecules or gas isotope molecules to be analyzed can be selectively separated by switching the gas flow by the flow channel switching unit or the like. Further, the gas channel space between the concentration unit and the channel switching unit provided downstream of the channel switching unit or the isotope channel switching unit or the isotope between the isotope concentration unit and the isotope channel switching unit. Gas molecules and the like selectively separated can be temporarily stored in the body channel space . At this time, the gas molecules introduced into the sample gas or isotope separation unit is introduced into the component separating unit, for introduction into the column by batchwise by setting the amount determined in advance, the space or the like of the gas flow path according Will gradually accumulate and store the separated hydrogen molecules. Thereby, it becomes possible to concentrate only a desired gas molecule or gas isotope molecule to a high concentration, and further, detection and analysis can be performed by a detector connected downstream. In addition, the concentrated gas molecules are reintroduced into the sample gas introduction part via the circulation channel connected to the concentration part, or the gas isotope molecules are passed through the isotope circulation channel connected to the isotope enrichment part. And can be reintroduced into the concentrated gas introduction part. Thereby, other gas molecules such as oxygen molecules mixed while being stored in the space of the gas flow path can be re-separated by each column. As a result, it is possible to further improve the purity of the gas molecules delivered to the detector or the like and eliminate the factors that hinder the analysis.

  Hereinafter, a gas separation and concentration apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. Here, FIG. 1 is an explanatory view schematically showing a schematic configuration of the gas separation / concentration device 1 of the present embodiment, and FIG. 2 shows a separation / concentration process of the hydrogen molecules 3 by the component separation unit 2 of the gas separation / concentration device 1. FIG. 3 is an explanatory view schematically showing, FIG. 3 is an explanatory view schematically showing the separation and concentration process of the hydrogen isotope molecule 5 by the isotope separation unit 4 of the gas separation and concentration apparatus 1, and FIG. 4 is a gas separation and concentration apparatus. FIG. 5 to FIG. 6 are diagrams schematically illustrating a final separation process before analysis by one final separation unit 6, and FIGS. 5 to 6 show a flow of separation and concentration processes of hydrogen molecules 3 and hydrogen isotope molecules 5 in the gas separation and concentration apparatus 1. It is a flowchart which shows. Here, the hydrogen molecule 3 corresponds to the gas molecule in the present invention, and the hydrogen isotope molecule 5 corresponds to the gas isotope molecule in the present invention. Further, in the isotope separation unit 4 of the gas separation and concentration apparatus 1 of the present embodiment, an example is shown that separates the “tritium-tritium” hydrogen isotope molecule 5 contained in the sample gas 7.

  As shown mainly in FIGS. 1 to 4, the gas separation / concentration device 1 of this embodiment includes a component separation unit 2 that separates and concentrates hydrogen molecules 3 from an introduced sample gas 7, and separated hydrogen. The hydrogen isotope molecule 5 to be analyzed is further separated from the molecule 3 and separated by the isotope separation unit 4 and the component separation unit 2 and / or the isotope separation unit 4, respectively. Before analyzing the hydrogen isotope molecule 5, it is mainly comprised including the final separation part 6 which performs a final component separation process. The final separation unit 6 is directly connected to an existing detector 8 that can detect the hydrogen molecules 3 and the like.

More specifically, the component separation unit 2 includes a sample gas 7 (a hydrogen molecule 3 and a hydrogen isotope molecule 5) supplied from a sample gas supply source (not shown) as mainly shown in FIG. ) Are introduced into the separation column 11 by a preset amount (set volume) in advance, and the separation column 11 connected to the sample gas introduction unit 12 and wound in a coil shape. Gas separation column unit 13 that separates each gas component contained in sample gas 7 using the difference in holding time required for passage through separation column 11 and the separation column of gas separation column unit 13 11, and the separated hydrogen molecules 3 separated from the sample gas 7 are connected to the gas discharge ports 17. Separation gas flow path 1 A flow path switching 19 to flow switched respectively to, it is connected via a passage switching section 19 and the gas passage 15, the circulation passage for circulating the separation column 11 the hydrogen molecule 3 led again to the sample gas inlet 12 20. To flow the hydrogen molecule 3 having an increased concentration to the final separation unit 6 and to the isotope separation unit 4 for further separating the hydrogen isotope molecule 5 to be analyzed from the concentrated hydrogen molecule 3. The concentrated gas flow path 22 can be switched to flow , and the flow path ports 20a, 20b, and 20c of the circulation flow path 20, the analysis flow path 21, and the concentrated gas flow path 22 are all blocked. The hydrogen molecules 3 that are switched and flown from the flow path switching unit 19 according to the difference in holding time by the sample gas 7 introduced by the set amount are temporarily stored in the space of the gas flow path 15, and the concentration of the hydrogen molecules 3 is changed. Because, it is mainly configured by including a rectifying section 23 for concentrating. In this embodiment, neon gas is used as a carrier gas (not shown) for introducing the sample gas 7.

  Here, the gas separation column unit 13 of the component separation unit 2 has substantially the same configuration as a column used in an existing gas chromatograph analyzer and a heating mechanism such as an oven for heating and holding the column at a predetermined temperature. is doing. As described above, the retention time required for the passage through the separation column 11 is as follows. Among the compounds (gases) separated by heating, those having a small molecular weight have a short retention time, while those having a large molecular weight are retained. The time tends to be long, and the retention time is individually determined according to the separation column 11. Therefore, the hydrogen molecules 3 separated in the present embodiment reach the column outlet 14 with a relatively short holding time immediately after the introduction of the sample gas 7 into the separation column 11 by the sample gas introduction unit 12 and are separated. On the other hand, gas molecules other than the hydrogen molecules 3 (for example, nitrogen molecules and oxygen molecules contained in the atmosphere) are discharged from the column outlet 14 later than the hydrogen molecules 3. The Therefore, using the difference in retention time between the hydrogen molecule 3 and a gas molecule other than the hydrogen molecule 3 (corresponding to the separation gas 16), a process for switching the flow path switching unit 19 is performed as appropriate. The gas is selectively flowed to the gas flow path 15, while the other separation gas 16 is flowed to the separation gas flow path 18 connected to the gas discharge port 17 and discharged to the outside. Thereby, only the hydrogen molecule 3 can be selectively separated from the sample gas 7 using the separation principle of the column of the gas chromatograph analyzer.

Further, as shown in FIGS. 1 and 2, the concentrating unit 23 of the component separating unit 2 flows through the gas flow channel 15, and the hydrogen molecules 3 that have reached the concentrating unit 23 are transferred to the three flow channels 20, 21, and 22. Each can be switched and flowed. Here, as described above, the sample gas 7 of a predetermined set amount is introduced into the separation column 11 from the sample gas introduction unit 12, and the hydrogen molecules 3 separated each time are sent to the concentration unit 23. . At this time, by closing all the channel ports 20a, 21a, and 22a such as the three channels 20 connected to the concentration unit 23, the gas channel 15 between the concentration unit 23 and the channel switching unit 19 is closed . The hydrogen molecules 3 are concentrated in the space .

Further, by opening the channel port 20a of the circulation channel 20 connected to the concentration unit 23, the concentrated hydrogen molecules 3 are sent to the sample gas introduction unit 12, and the hydrogen molecules 3 are again supplied to the gas separation column unit 13. The components are separated by Thereby, gas molecules (oxygen molecules, etc.) other than the hydrogen molecules 3 mixed in the process of being stored in the space of the gas flow path 15 are separated again by the separation column 11, and are separated to the outside as the separation gas 16 by the flow path switching unit 19. Can be released. As a result, the hydrogen molecules 3 stored in the space of the gas flow path 15 are concentrated at a high concentration, and impurities that impede analysis are not mixed. On the other hand, by opening the channel port 21a leading to the analysis channel 21, the hydrogen molecules 3 can be guided to the final separation unit 6 and the final separation process before the analysis can be performed (details will be described later). Further, by opening the channel port 22a leading to the concentrated gas channel 22, the hydrogen molecule 3 can be guided to the isotope separation unit 4 and only the hydrogen isotope molecule 5 to be analyzed can be selectively separated. (Details will be described later). In addition, the switching process to each flow path and the timing of the switching operation in the flow path switching unit 19 and the concentration unit 23 described above are manually performed by an operator (user) who operates the gas separation and concentration apparatus 1 of the present embodiment. It may be performed, or may be switched automatically based on preset conditions.

  On the other hand, as shown in FIGS. 1 and 3, the isotope separation unit 4 of the present embodiment is connected to the component separation unit 2 via the concentrated gas flow path 22 and concentrated through the concentrated gas flow path 22. The hydrogen molecule introduction unit 25 that introduces the hydrogen molecules 3 into the cooling column 24 by a preset amount, and the cooling column 24 connected to the hydrogen molecule introduction unit 25 are cooled to an extremely low temperature state, An isotope separation column unit that selectively separates only the hydrogen isotope molecule 5 to be analyzed from a plurality of hydrogen isotope molecules contained in the hydrogen molecule 3 by utilizing the difference in holding time required for passing through the cooling column 24. 26 and the second column outlet 27 of the cooling column 24 of the isotope separation column section 26, and the separated hydrogen isotope molecule 5 flows to the isotope channel 28, while the hydrogen isotope 5 Residual gas after body molecule 5 is separated 9 is switched to the remaining gas flow path 30 connected to the gas discharge port 17, and isotope flow path switching unit 31 is connected to the isotope flow path switching unit 31, and hydrogen molecules 3 are introduced multiple times. Isotope circulation in which the hydrogen isotope molecule 5 separated according to is temporarily stored, the hydrogen isotope molecule 5 is concentrated, and the hydrogen isotope molecule 5 is led again to the hydrogen molecule introduction part 25 for circulation. It mainly comprises a flow channel 32 and an isotope enrichment unit 34 connected to an isotope analysis flow channel 33 for flowing the hydrogen isotope molecule 5 to the final separation unit 6. Here, the hydrogen molecule introduction unit 25 corresponds to the gas molecule introduction unit in the present invention, and the cooling column 24 corresponds to the isotope separation column in the present invention.

  More specifically, the cooling column 24 of the isotope separation column unit 26 is installed in a state of being immersed in a cooling container 36 filled with liquid nitrogen 35. Thereby, the inside of the cooling column 24 is cooled so as to be in a cryogenic state close to the boiling point (minus 196 ° C.) of the liquid nitrogen 35. Further, in the present embodiment, neon gas used in the component separation unit 2 is used here as a carrier gas when the hydrogen molecules 3 are introduced into the cooling column 24. Since this neon gas has physical properties that are lower than the boiling point of the liquid nitrogen 35, the neon gas does not liquefy in the cooling column 24 and can sufficiently function as a carrier gas.

  Further, the gas separation / concentration device 1 of the present embodiment is separated and concentrated in the component separation unit 2, and separated and concentrated in the hydrogen molecule 3 or isotope separation unit 4 sent from the concentration unit 23 via the analysis flow path 21. Each of the hydrogen isotope molecules 5 sent from the isotope enrichment section 34 via the isotope analysis flow path 33 is configured to have a final separation section 6 that performs final separation before analysis. Here, the final separation unit 6 is connected to the analysis flow path 21 extending from the component separation unit 2, introduces the hydrogen molecules 3 that are sent out into the component separation column 37 heated to a predetermined temperature, A pre-analysis gas separation column section 38 that separates the components mixed in the hydrogen molecules 3 using the difference in retention time required for passing through the column 37, and an isotope analysis flow path 33 that extends from the isotope separation section 4. The hydrogen isotope molecule 5 is introduced into an isotope separation / cooling column 39 cooled to a predetermined cryogenic temperature, and mixed in the hydrogen isotope molecule 5 by utilizing the difference in holding time required to pass through the column 39. And a pre-analysis isotope separation column section 40 for separating other hydrogen isotope molecules 5a and the like. Here, the component separation column 37 of the pre-analysis gas separation column unit 38 has the same configuration as the separation column 11 of the component separation unit 2, while the isotope separation cooling of the pre-analysis isotope separation column unit 40. The column 39 has the same configuration as that of the cooling column 24 of the isotope separation unit 4, and is immersed in a cooling container 41 filled with liquid nitrogen 35 in the same manner as the cooling column 24. The pre-analysis gas separation column section 38 and the pre-analysis isotope separation column section 40 are connected to a detector 8 for detecting and analyzing the components separated for each component by such processing. Here, the isotope separation cooling column 39 corresponds to the isotope component separation column in the present invention.

  Next, an example of use of the gas separation / concentration device 1 of the present embodiment will be described based on the explanatory diagrams of FIGS. 1 to 4 and the flowcharts of FIGS. 5 and 6. First, the sample gas 7 is supplied from the sample gas supply source (not shown) to the component separation unit 2 of the gas separation and concentration apparatus 1. At this time, as the carrier gas used for transporting the sample gas 7, as described above, an inert neon gas that is not liable to be liquefied or solidified at an extremely low temperature is used. Before introducing the sample gas 7, only neon gas is sent to the gas separation / concentration device 1 in advance, and the sample gas introduction unit 12, the separation column 11, the channel switching unit 19, the concentration unit 23, and each channel 20, etc. By passing through, pretreatment for replacing nitrogen molecules, oxygen molecules, etc. present in the atmosphere is performed (step S0). Then, a preset amount of the sample gas 7 from the sample gas introduction unit 12 is introduced into the separation column 11 of the gas separation column unit 13 by a batch method (step S1).

  At this time, the separation column 11 into which the sample gas 7 has been introduced is in a state of being heated to a predetermined heating temperature in order to separate the hydrogen molecules 3 from the sample gas 7 by a heating mechanism such as an oven. Then, the introduced sample gas 7 passes through the separation column 11 and reaches the column outlet 14 to be separated into each component (including atmospheric components) constituting the sample gas 7 (step) S2). Then, the flow path switching unit installed at the column outlet 14 using the difference of each component in the time (holding time: retention time) required to reach the column outlet 14 immediately after the start of the introduction of the sample gas 7 The switching operation by 19 is performed (step S3).

  Here, it is known that the low molecular weight hydrogen molecules 3 reach the column outlet 14 in a relatively short time immediately after the introduction of the sample gas 7 into the separation column 11 is started. Therefore, when a predetermined time has not elapsed since the start of the introduction of the sample gas 7 (YES in step S3), the gas discharged from the column outlet 14 (mainly equivalent to the hydrogen molecule 3) flows through the gas flow path 15. Thus, the switching process is performed by the flow path switching unit 19 (step S4). On the other hand, when a predetermined time has passed since the start of introduction of the sample gas 7 (NO in step S3), the gas discharged from the column outlet 14 (mainly equivalent to the separation gas 16) flows into the separation gas flow path 18. Thus, the switching process is performed in the flow path switching unit 19 (step S5), and the separation gas 16 is discharged to the outside through the gas discharge port 17 (step S6). In the present embodiment, the switching operation of the flow path switching unit 19 is achieved by an operator determining the switching timing with a clock or the like and performing it manually.

Then, the hydrogen molecules 3 that have flowed into the gas flow path 15 by the switching of the flow path switching unit 19 are temporarily stored in this space (step S7). Thereafter, a flow path after the hydrogen molecules 3 stored in the space are flowed is determined (step S8). That is, the hydrogen molecules 3 that have reached the space of the gas flow channel 15 and are temporarily stored are concentrated to a high concentration, and the concentration state progresses to such a level that it can be detected with high sensitivity by the detector 8 or the like described later. If it is determined that almost no impurities are mixed (YES in step S8), in other words, if the concentration is complete, the hydrogen molecules 3 are sent to the final separation unit 6 connected to the detector 8. Or a step of determining whether or not only the specific hydrogen isotope molecule 5 is further separated from the concentrated hydrogen molecule 3 and concentrated (step S9). On the other hand, when the concentration of the hydrogen molecules 3 is not completed or there is a high possibility that impurities are mixed (NO in step S8), in other words, when the concentration is not completed , The temporarily stored hydrogen molecules 3 are introduced into the sample gas introduction unit 12 and the gas separation column unit 13 again separates impurities and the like, or a new sample gas 7 is separated by the sample gas introduction unit 12. The step of re-introducing into the separation column 11 of the column section 13 and determining whether or not new hydrogen molecules 3 are accumulated and stored in the space of the gas flow path 15 is performed (step S10).

Here, when the sample gas introduction unit 12 reintroduces the new sample gas 7 into the gas separation column unit 13 (YES in step S10), the new sample gas 7 is introduced (step S11). Then, returning to the process of step S <b> 2, a repetitive process of selectively separating only the hydrogen molecules 3 by the gas separation column unit 13 and the flow path switching unit 19 and sending it to the space of the gas flow path 15 is performed. On the other hand, when the sample gas 7 is not reintroduced, the concentration unit 23 is switched, and the hydrogen molecules 3 stored in the space of the gas channel 15 through the circulation channel 20 are sent to the sample gas introduction unit 12 ( In step S10, NO), the channel port 20a of the circulation channel 20 connected to the concentration unit 23 is opened, and the hydrogen molecules 3 are guided to the sample gas introduction unit 12 (step S12). Then, hydrogen molecules 3 which has reached the sample gas inlet 12 again returns to the processing in step S3, is included in the hydrogen molecule 3 which is enrichment, the detector 8 factors become impurities (shown to lower the detection accuracy of such Not) can be separated and removed by the gas separation column section 13. As a result, the highly purified and concentrated hydrogen molecules 3 are stored again in the space of the gas flow path 15 .

  On the other hand, the above-described steps of concentration of the hydrogen molecules 3 and purification for removing impurities from the concentrated hydrogen molecules 3 are repeatedly performed, and the highly purified and concentrated hydrogen molecules 3 are stored in the concentration unit 23. If it is determined (YES in step S8), that is, if the concentration is completed, the flow path for sending the hydrogen molecules 3 is determined as either the analysis flow path 21 or the concentrated gas flow path 22 as described above. Steps are performed (step S9). Here, when the separated and concentrated hydrogen molecule 3 is detected and analyzed by the detector 8 (YES in step S9), that is, when the hydrogen isotope molecule 5 is not separated, the analysis connected to the final separation unit 6 is performed. The flow channel port 21a communicating with the flow channel 21 is opened, and the hydrogen molecules 3 are sent out (step S13). On the other hand, when only the specific hydrogen isotope molecule 5 is selectively separated from the separated and concentrated hydrogen molecule 3 (NO in step S9), the concentrated gas flow connected to the hydrogen molecule introduction unit 25 of the isotope separation unit 4 The flow path port 22a is opened so that the hydrogen molecules 3 flow in the path 22, and the flow is sent out (step S14).

  Then, the specific hydrogen isotope molecule 5 is separated and concentrated from the hydrogen molecule 3 sent to the hydrogen molecule introduction unit 25 of the isotope separation unit 4 (step S15). Here, each configuration in the isotope separation unit 4 is substantially the same as the configuration of the component separation unit 2 described above, and the separation and concentration process of the hydrogen molecule 3 described above also for the separation and concentration process of the hydrogen isotope molecule 5. Since the flow is substantially the same as that described above, detailed description thereof will be omitted. That is, the hydrogen molecule introduction unit 25 is the sample gas introduction unit 12, the isotope separation column unit 26 is the gas separation column unit 13, the isotope channel switching unit 31 is the channel switching unit 19, and the isotope concentrating unit 34 is the concentrating unit. 23 has substantially the same function.

  Here, as described above, it is known that six types of hydrogen isotope molecules 5 exist by a combination of light hydrogen, deuterium, and tritium. Among these combinations, the hydrogen isotope molecule 5b composed of the combination of “light hydrogen-light hydrogen” has the shortest retention time from the column (cooling column 24) kept at an extremely low temperature. On the other hand, it is known that the hydrogen isotope molecule 5c composed of a combination of “tritium-tritium” tends to have the longest retention time. Therefore, in the separation and concentration process of the hydrogen isotope molecule 5 in step S15, the hydrogen isotope molecule 5 selected from the respective hydrogen isotope molecules 5a and the like (in this embodiment, “tritium − The isotope flow path switching unit 31 is switched with reference to the retention time set according to the combination of “tritium”. On the other hand, the residual gas 29 including the hydrogen isotope molecule 5 a and the like other than the analysis target is discharged from the gas discharge port 17 into the residual gas flow path 30. In addition, a slight amount of impurities may be mixed in the hydrogen molecules 3 passing through the inside of the cooling column 24 cooled to a very low temperature by the liquid nitrogen 35. Here, when passing through the cooling column 24 cooled to minus 196 ° C., such impurities generally have a boiling point or melting point higher than minus 196 ° C., so that they are liquefied or solidified in the cooling column 24. As a result, the second column outlet 27 cannot be reached, and impurities are collected in the cooling column 24. Therefore, the isotope separation column unit 26 also has a function of removing impurities from the hydrogen molecules 3.

  The hydrogen isotope molecule 5 obtained by separating and concentrating only the specific hydrogen isotope molecule 5 from the hydrogen molecule 3 is supplied to the final separation unit 6 by substantially the same flow as the separation and concentration process in the component separation unit 2 described above. It is sent out through the isotope analysis flow path 33 (step S16). Then, re-separation processing of the hydrogen molecule 3 or the hydrogen isotope molecule 5 sent out in step S13 or step S16 is performed. Here, the hydrogen molecules 3 are introduced into the heated component separation column 37 of the pre-analysis gas separation column section 38, and the component separation process is performed again (step S17), while the hydrogen isotope molecules 5 are pre-analyzed. The isotope separation column section 40 is introduced into the isotope separation cooling column 39 cooled to an extremely low temperature, and isotope separation processing is performed again (step S18). Thereby, the final component separation processing of the hydrogen molecule 3 and the hydrogen isotope molecule 5 is performed immediately before being sent to the detector 8, and each component (hydrogen molecule 3 or hydrogen isotope molecule in the detector 8 is processed. Detection and analysis of 5) are performed with high sensitivity. Then, after the final separation process in the final separation unit 6, the analysis is performed in the detector 8 (step S19 and step S20).

As described above, according to the gas separation and concentration apparatus 1 of this embodiment, the hydrogen molecules 3 are selectively selected by the component separation unit 2 from the sample gas 7 including the hydrogen molecules 3 and the hydrogen isotope molecules 5 to be analyzed. On the other hand, a specific hydrogen isotope molecule 5 can be selectively separated and concentrated by the isotope separation unit 4. In particular, the hydrogen molecules 3 and the like are separated by utilizing the difference in holding time required for passing through each column 11 and the like, and the sample gas 7 or the hydrogen molecules 3 are introduced into the column 11 and the like by a predetermined set amount. Since it can be concentrated in the space of the gas flow path 15 by the “batch method”, the hydrogen molecules 3 to be analyzed can be easily concentrated. In addition, the hydrogen molecules 3 and the like stored in the space of the gas channel 15 and the like are switched by the concentration unit 23 and the like, and again pass through the column 11 and the like through the circulation channel 20 and the like , and impurities mixed at the time of storage Can be removed from the hydrogen molecule 3 and then sent to the next process (isotope separation process or final separation process). The final separation unit 6 can separate each component as a final stage before analysis, and the detector 8 can perform detection and analysis. As a result, the sample gas 7 is repeatedly passed through a plurality of columns 11 and the like until reaching the detector 8, so that impurities that exist in a very small amount due to the separation process and reduce detection accuracy are eliminated. Analysis can be performed with sensitivity. In addition, by performing final component separation before analysis by the final separation unit 6, the accuracy of analysis can be further improved. Furthermore, compared to the separation using a conventional concentration tube, the concentration processing time can be greatly shortened, and the concentration can be increased to a high concentration by a relatively simple operation. Furthermore, the gas separation / concentration device of this embodiment makes it possible to perform a specific gas isotope molecule concentration process, which was difficult with a concentration tube.

  The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention as described below. And design changes are possible.

  That is, in the gas separation and concentration apparatus 1 of the present embodiment, the hydrogen molecule 3 and the hydrogen isotope molecule 5 that is an isotope thereof are exemplified as gas molecules to be analyzed. However, the present invention is not limited to this. Other gas molecules may be subjected to separation and concentration treatment by the gas separation and concentration apparatus 1 of the present invention. In such a case, it is necessary to appropriately switch the flow path switching process by the flow path switching unit 19 or the isotope flow path switching unit 31 according to the difference in retention time depending on the gas molecule to be analyzed. Furthermore, in the separation of the gas isotope molecules, a cooling agent such as liquid nitrogen is used to perform the separation by the cooling column 24 brought to a cryogenic state. However, the present invention is not limited to this. It may be one that uses another different coolant, or one that performs separation for each gas isotope molecule by another method.

It is explanatory drawing which shows typically schematic structure of the gas separation concentration apparatus of this embodiment. It is explanatory drawing which shows typically the separation-concentration process of the hydrogen molecule by the component separation part of a gas separation concentration apparatus. It is explanatory drawing which shows typically the isolation | separation concentration process of the hydrogen isotope molecule | numerator by the isotope separation part of a gas separation concentration apparatus. It is explanatory drawing which shows typically the final separation process before the analysis by the final separation part of a gas separation concentration apparatus. It is a flowchart which shows the flow of a separation process of a hydrogen molecule and a hydrogen isotope molecule in a gas separation concentration apparatus. It is a flowchart which shows the flow of a separation process of a hydrogen molecule and a hydrogen isotope molecule in a gas separation concentration apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas separation concentrator 2 Component separation part 3 Hydrogen molecule (gas molecule)
4 Isotope separation part 5,5a, 5b, 5c Hydrogen isotope molecule (gas isotope molecule)
6 Final separation unit 7 Sample gas 8 Detector 11 Separation column 12 Sample gas introduction unit 13 Gas separation column unit 14 Column outlet 15 Gas channel 16 Separation gas 17 Gas discharge port 18 Separation gas channel 19 Channel switching unit 20 Circulating flow Path 21 Analysis channel 22 Concentrated gas channel 23 Concentration unit 24 Cooling column (isotope separation column)
25 Hydrogen molecule introduction part (gas molecule introduction part)
26 Isotope separation column section 27 Second column outlet 28 Isotope flow path 29 Residual gas 30 Residual gas flow path 31 Isotope flow path switching section 32 Isotope circulation flow path 33 Isotope analysis flow path 34 Isotope enrichment section 37 Components Separation column 38 Gas separation column part before analysis 39 Isotope separation cooling column (isotope component separation column)
40 Pre-analytical isotope separation column

Claims (3)

A sample gas introduction part for introducing a sample gas containing gas molecules to be analyzed by a preset amount;
A gas separation column unit that is connected to the sample gas introduction unit and separates the gas molecules from the sample gas introduced by a set amount by using a difference in retention time required to pass through the separation column;
The separated gas molecules, which are installed at the column outlet of the separation column of the gas separation column section and flow into the gas flow path, are separated from the sample gas by the gas separation column section. A flow path switching unit for switching to flow to the separation gas flow path connected to the gas discharge port based on the difference in holding time required to pass through the separation column, and
A circulation channel that is connected to the channel switching unit via the gas channel and leads the gas molecule to the sample gas introduction unit in order to pass the gas molecule again through the separation column, and the concentration is increased. An analysis flow path for guiding the gas molecules to a final separation unit , and a concentrated gas flow connected to the gas molecule introduction unit for introducing the gas molecules to perform a process of separating the gas isotope molecules to be analyzed from the gas molecules Each of the circulation channels, the analysis channel, and the concentrated gas channel can be closed by closing each channel port, so that the sample gas introduced by a set amount can be used. A concentration unit that temporarily stores the gas molecules that are switched and flowed from the channel switching unit according to a difference in holding time in the space of the gas channel, and increases and concentrates the concentration of the gas molecules;
The gas molecule introduction unit that is connected to the concentration unit via the concentrated gas flow path and introduces the gas molecules by a preset amount;
An isotope separation column section that is connected to the gas molecule introduction section and separates the gas isotope molecules from the gas molecules introduced by a set amount by using a difference in retention time required for passage through the isotope separation column;
The isotope separation column unit is installed at the second column outlet of the isotope separation column, and the separated gas isotope molecules are flowed to the isotope flow path, and the isotope separation column unit from the gas molecules An isotope channel switching unit that switches the residual gas from which gas isotope molecules have been separated to a residual gas channel connected to the gas discharge port based on a difference in holding time required to pass through the isotope separation column; ,
An isotope circulation channel connected to the isotope channel switching unit through the isotope channel and leading to the gas molecule introduction unit to pass the gas molecule again through the isotope separation column; and The gas isotope molecules can be switched to the isotope analysis flow path for flowing to the final separation unit , and the flow path ports of the isotope circulation flow path and the isotope analysis flow path are both closed. By this, the gas isotope molecules that are switched and flowed by the difference in retention time from the isotope channel switching unit by the gas molecules introduced by a set amount are temporarily stored in the space of the isotope channel, A gas separating and concentrating apparatus comprising: an isotope concentrating unit that increases and concentrates the concentration of the gas isotope molecule. The final separation part is
A pre-analysis gas that is connected to the concentrating unit via the analysis flow path and separates the gas molecules whose concentration is increased in the space of the gas flow path using the difference in retention time required to pass through the component separation column The gas separation / concentration apparatus according to claim 1, further comprising a separation column unit. The final separation part is
The difference in retention time required for the gas isotope molecule connected to the isotope enrichment section through the isotope analysis flow channel and having the concentration increased in the space of the isotope flow channel to pass through the isotope component separation column The gas separation / concentration apparatus according to claim 1 or 2, further comprising a pre-analyte isotope separation column section for separation using a gas.

Images