Gas analyzer

Abstract

A gas analysis device for detecting greenhouse effect gas contained in a sample gas is provided with: a carrier gas supply unit (115) for supplying nitrogen as a carrier gas to each of two different flow paths; a sample introduction unit (113) that introduces the sample gas into each of the two different flow paths; a first column (111) and a second column (112) connected to the two different flow paths, respectively; a hydrogen flame ionization detector (116) connected to the first chromatographic column; a methanator (118) for reducing the carbon dioxide, which has flowed out from the first column and has flowed into the flame ionization detector, to methane; and an electron capture detector (117) connected to the second chromatographic column. With this configuration, it is possible to simplify the configuration of an analysis device for analyzing greenhouse gas, and to reduce the operating cost of the analysis by the gas analysis device.

Description

Technical Field

[0001] This invention relates to a gas analysis apparatus. Background Technology

[0002] In gas analysis devices based on gas chromatography, appropriate detectors are required depending on the type of compound being detected. For example, when analyzing methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O), which are major greenhouse gases, CH4 is detected using a flame ionization detector (FID), CO2 using a thermal conductivity detector (TCD), and N2O using an electron capture detector (ECD).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2017 / 138646 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] Therefore, when simultaneously analyzing CH4, CO2, and N2O, the gas analysis apparatus requires three detectors and a complex valve system (see, for example, Patent Document 1) for switching the flow paths of the carrier gas and sample gas, thus complicating the apparatus configuration. Furthermore, to achieve high-precision CO2 detection via TCD, He gas is required as the carrier gas; however, He is currently in short supply globally, leading to soaring prices. Additionally, nitrogen (N2) is typically used as the detector gas in ECD (the gas introduced into the detector based on its detection principle). However, for high-precision N2O detection via ECD, argon gas containing 5% methane (hereinafter referred to as "Ar + 5% CH4") is required as the detector gas. Therefore, in this case, the operating cost increases compared to using N2.

[0008] That is, the first technical problem of the present invention is to simplify the configuration of the analytical apparatus for analyzing greenhouse gases and to reduce the operating cost of analysis based on the gas analytical apparatus. Furthermore, the second technical problem of the present invention is that, in the analytical apparatus for analyzing greenhouse gases, when detecting N2O by ECD, detection can be performed with sufficient sensitivity even without using Ar + 5% CH4 as the detector gas.

[0009] Solution to the above technical problems

[0010] The gas analysis apparatus according to the first aspect of the present invention, which was completed to solve the above-mentioned technical problems, is a gas analysis apparatus for detecting greenhouse gases contained in a sample gas, and has the following features:

[0011] The carrier gas supply unit supplies nitrogen as carrier gas to two different flow paths;

[0012] The sample inlet section introduces the sample gas into the two different flow paths respectively;

[0013] The first and second chromatographic columns are respectively connected to the two different flow paths;

[0014] A hydrogen flame ionization detector is connected to the first chromatographic column;

[0015] The methanator reduces carbon dioxide flowing from the first chromatographic column and into the flame ionization detector to methane.

[0016] An electron capture detector is connected to the second chromatographic column.

[0017] The gas analysis apparatus according to the second aspect of the present invention, which was completed to solve the above-mentioned technical problems, is a gas analysis apparatus for detecting greenhouse gases contained in a sample gas, and has the following features:

[0018] Adsorption chromatographic columns;

[0019] The sample introduction section introduces the sample gas into one end of the adsorption-type chromatographic column;

[0020] An electron capture detector is connected to the other end of the adsorption column;

[0021] The detector gas supply unit supplies nitrogen as the detector gas to the electron capture detector;

[0022] Column oven, which houses the adsorption-type chromatographic column;

[0023] Temperature control unit, used to regulate the temperature inside the column oven;

[0024] The control unit controls the temperature control unit in the following manner: at the time point when the sample gas is introduced into the adsorption-type chromatographic column, the temperature inside the column oven is set to a temperature lower than a first temperature, the first temperature being the upper limit of the temperature at which nitrous oxide is adsorbed into the adsorption-type chromatographic column and does not detach; thereafter, the temperature inside the column oven is raised to a temperature above the first temperature.

[0025] Invention Effects

[0026] According to the gas analysis apparatus of the first aspect of the present invention, the configuration of the analysis apparatus for analyzing greenhouse gases can be simplified, and the operating cost of the analysis can be reduced.

[0027] According to the gas analysis apparatus of the second aspect of the present invention, in an analysis apparatus for analyzing greenhouse gases, N2O can be detected with sufficient sensitivity even without using Ar + 5% CH4 as the detector gas for ECD. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a gas analysis apparatus according to one embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of a gas analysis apparatus according to another embodiment of the present invention.

[0030] Figure 3 This is a chromatogram showing the measurement results of CH4 and CO2 in the atmosphere in one embodiment of the present invention.

[0031] Figure 4 This is a chromatogram showing the measurement results of N2O in the atmosphere in this embodiment. Detailed Implementation

[0032] Hereinafter, the methods for carrying out the present invention will be described with reference to the accompanying drawings. Figure 1 This is a schematic diagram of a gas analysis apparatus according to one embodiment of the present invention.

[0033] The gas analysis apparatus of this embodiment simultaneously analyzes methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O), which are major greenhouse gases, using gas chromatography. This gas analysis apparatus includes: a column oven 110; a first chromatographic column 111 and a second chromatographic column 112 housed in the column oven 110; a sample inlet 113 connected to the inlet ends of the first chromatographic column 111 and the second chromatographic column 112; an automatic sampler 114 that injects multiple pre-prepared sample gases into the sample inlet 113 in a predetermined order; a carrier gas supply unit 115 that supplies carrier gas to the sample inlet 113; a flame ionization detector (FID) 116 connected to the outlet end of the first chromatographic column 111; and an electron capture detector (ECD) 117 connected to the outlet end of the second chromatographic column 112. The system includes: a methanator 118 installed in the FID 116; a detector gas supply unit 119 for the FID supplying detector gas to the FID 116; a detector gas supply unit 120 for the ECD supplying detector gas to the ECD 117; a heater 121 and a temperature sensor 122 disposed within the column oven 110; a heater drive unit 123 supplying heating current to the heater 121; a temperature control unit 124 controlling the heater drive unit 123 to achieve a target temperature within the column oven 110 based on input from the temperature sensor 122; and a control unit 125 controlling all of the above units. In this embodiment, the control unit 125 corresponds to the control unit and detector gas supply control unit in this invention, and the heater 121, temperature sensor 122, heater drive unit 123, and temperature control unit 124 correspond to the temperature control unit in this invention.

[0034] The control unit 125 is centered around a microcomputer including a CPU, RAM, ROM, etc. Furthermore, at least a portion of the functions of the control unit 125 can be implemented by executing dedicated control software pre-installed on the personal computer.

[0035] Both the first chromatographic column 111 and the second chromatographic column 112 are capillary columns or micro-packed columns (packed columns with an inner diameter of less than 1 mm). The inlet ends of these columns 111 and 112 are connected to the sample inlet 113 via a branch adapter 126. The branch adapter 126 branches the gas flow from the sample inlet 113 into two branches, each with one inlet and two outlets. The inlet is connected to the gas outlet of the sample inlet 113, and one of the two outlets is connected to the inlet end of the first chromatographic column 111, and the other is connected to the inlet end of the second chromatographic column 112.

[0036] The second chromatographic column 112 is an adsorption-type chromatographic column for component separation based on gas-solid chromatography. The stationary phase held in the adsorption-type chromatographic column can be anything capable of adsorbing N₂O. For example, an adsorbent composed of porous particles can be used as such a stationary phase. Examples of adsorbents composed of these porous particles include alumina, activated carbon, zeolite, or silica gel. More specifically, as an adsorbent composed of these porous particles, a molecular sieve composed of synthetic zeolite particles is preferred. Furthermore, it is desirable to use a molecular sieve with a pore size of 0.3 nm or more (more preferably 0.4 nm or more).

[0037] On the other hand, the first chromatographic column 111 can be any chromatographic column as long as it can clearly separate CH4 and CO2. For example, in addition to the adsorption type chromatographic column described above, a partition type chromatographic column based on gas-liquid chromatography for component separation can also be used. Furthermore, as the partition type chromatographic column, a chromatographic column in which a non-volatile liquid is held against the inner wall of a carrier particle or capillary can be used. Moreover, as the aforementioned non-volatile liquid, for example, liquid phases commonly used in capillary chromatography columns, such as methylsilyl-based, phenylmethyl-based, cyanopropylphenyl-based, trifluoropropyl-based, or polyethylene glycol-based liquid phases, can be used.

[0038] The carrier gas supply unit 115, the FID detector gas supply unit 119, and the ECD detector gas supply unit 120 all include a gas source (not shown) consisting of a gas cylinder or a gas generating device, and an adjustment mechanism (not shown) for adjusting the flow rate, pressure, or linear velocity of the gas flowing from the gas source. In this embodiment, the carrier gas supply unit 115 supplies N2 as the carrier gas to the sample introduction unit 113. Furthermore, the FID detector gas supply unit 119 supplies H2 and air as detector gas (the gas required to detect the target component) to the FID 116, and the ECD detector gas supply unit 120 supplies N2 as the detector gas to the ECD 117.

[0039] Methanator 118 reduces CO2 to CH4 through a reaction with H2. In this embodiment, the injection-type methanator 118 is installed inside FID 116. The injection-type methanator 118 is formed by filling the nozzle (injection) of FID 116 with catalyst. However, the methanator 118 in this embodiment is not limited to the injection type; for example, it can also be a tubular methanator formed by filling a tube with nickel catalyst. In this case, the tubular methanator is inserted into the gas flow path between the outlet end of the first column 111 and FID 116 using a flow path switching valve or the like.

[0040] When performing analysis using the gas analysis apparatus according to this embodiment, firstly, carrier gas (i.e., N2) is supplied from the carrier gas supply unit 115 to the sample inlet unit 113 at a predetermined constant flow rate, pressure, or linear velocity. The flow of this carrier gas is divided into two at a predetermined ratio by a branch adapter 126 provided immediately after the sample inlet unit 113, one of which flows in the first chromatographic column 111 to reach FID 116, and the other flows in the second chromatographic column 112 to reach ECD 117.

[0041] Next, with the carrier gas flowing as described above, a predetermined amount of sample gas is injected from the autosampler 114 into the sample inlet 113, thereby sending the sample gas into the first chromatographic column 111 and the second chromatographic column 112 along with the carrier gas flow. At this time, the temperature inside the column oven 110 is set to a temperature lower than a first temperature at the point when the sample gas reaches the inlet of the second chromatographic column 112. The first temperature is the upper limit of the temperature at which N2O is adsorbed in the chromatographic column 112 and does not detach. Then, the temperature is gradually increased to a temperature higher than the first temperature. Specifically, for example, the control unit 125 controls the temperature control unit 124 in the following manner: at the point when the sample gas is injected into the sample inlet 113, the temperature inside the column oven 110 is preset to below 50°C. Then, at a point when a predetermined time has elapsed since the sample gas reached the inlet of the second chromatographic column 112, the temperature of the column oven 110 is started to rise. Furthermore, the time from injecting the sample gas into the sample inlet 113 to the sample gas reaching the inlet of the second chromatographic column 112 can be determined in advance through experiments or calculations. Afterwards, the heating is stopped at the point when the temperature inside the column oven 110 reaches a predetermined temperature (e.g., 200°C to 300°C, more preferably 210°C to 250°C), and this temperature is maintained for a specified time.

[0042] Various sample components contained in the sample gas are separated in the time direction as they pass through the first chromatographic column 111 or the second chromatographic column 112 along with the carrier gas flow, resulting in a time difference that allows them to reach FID 116 or ECD 117 for detection. In this embodiment, CO2 and CH4 eluted from the first chromatographic column 111 are detected by FID 116, and N2O eluted from the second chromatographic column 112 is detected by ECD 117. In the first chromatographic column, CH4 first elutes from the outlet and is detected by FID 116, and then CO2 elutes from the first chromatographic column 111 at a time interval, is reduced to CH4 by the methanator 118, and is then detected by FID 116. On the other hand, in the second chromatographic column 112, N2O is temporarily adsorbed by the adsorbent near the inlet of the column 112, and then the temperature inside the column oven 110 exceeds the first temperature, thereby causing N2O to detach from the adsorbent and elute from the outlet of the second chromatographic column 112 for detection by ECD 117.

[0043] Thus, in the gas analysis apparatus according to this embodiment, CO2 eluted from the first chromatographic column 111 and flowing into FID 116 is reduced to CH4 by the methanator 118 and then detected by FID 116. This allows for high-sensitivity detection of CO2 without the use of a TCD. Therefore, compared to the conventional configuration using three detectors (i.e., FID, TCD, and ECD), the apparatus configuration is simplified and manufacturing costs are reduced. Furthermore, while conventional high-sensitivity detection of CO2 by TCD requires the use of He as a carrier gas, the gas analysis apparatus according to this embodiment can detect CO2 with high sensitivity without using a TCD, thus eliminating the need for expensive and difficult-to-obtain stable He as a carrier gas. Moreover, in the high-sensitivity detection of CH4 and CO2 in FID 116 and the high-sensitivity detection of N2O in ECD 117 of this embodiment, relatively inexpensive N2 can be used as a carrier gas, saving the effort of preparing multiple carrier gases and reducing analytical operating costs.

[0044] Furthermore, as described above, N2O is concentrated by introducing it into the ECD117 via the second chromatographic column 112, which is an adsorption-type chromatographic column. Therefore, even without using Ar + 5% CH4 as the conventional detector gas, N2O can be detected with sufficient sensitivity in the ECD117. As a result, in the gas analysis apparatus according to this embodiment, the gases required for analysis (i.e., carrier gas and detector gas) are only the relatively inexpensive and readily available N2, H2, and air, thus reducing the time and cost of preparing the gases required for analysis.

[0045] Furthermore, if a large amount of O2 flows into the interior of ECD117, there is a risk that the deterioration of ECD117 will be accelerated. However, in the gas analysis apparatus according to this embodiment, by performing N2O concentration as described above, N2O and O2 can be eluted from the second chromatographic column 112 with a sufficient time difference. Therefore, by increasing the flow rate of the detector gas supplied to ECD117 at the time when O2 is eluted from the second chromatographic column 112, the effect of O2 on ECD117 can be suppressed. Specifically, the control unit 125 controls the detector gas supply unit 120 for ECD in such a way that the flow rate of the detector gas (i.e., N2) introduced into ECD117 is increased within a predetermined time before and after the retention time of O2 in the second chromatographic column 112 (hereinafter referred to as the O2 elution time) from the time point when the sample gas is introduced into the sample introduction unit 113. For example, within a range of 30 seconds to 2 minutes (more preferably 1 minute before and after) before and after the O2 elution time. Therefore, a large amount of N2 can be used to dilute the O2 flowing into the ECD117, and the O2 can be quickly discharged from the ECD117.

[0046] The present invention has been described above with specific examples, but it is not limited to the above embodiments and can be appropriately modified within the scope of the spirit of the invention. For example, in the above embodiments, the sample gas is automatically introduced into the sample introduction section 113 by the automatic sampler 114, but it is not limited thereto. It may also be configured so that the sample gas is introduced into the sample introduction section 113 manually by the user operating a syringe. In addition, it may be configured to use a gas sampler equipped with a metering tube, and after the sample gas is guided from the sample gas container to the metering tube, the sample gas is introduced into the sample introduction section from the metering tube.

[0047] Furthermore, in the above embodiment, N2O is concentrated at the inlet of the second column 112 before being sent to the ECD 117. However, it can also be configured so that such concentration is not performed, that is, the column oven 110 based on the temperature control unit 124 is not heated as described above, or a partition-type column is used as the second column 112. In addition, in this case, it is desirable to use Ar + 5% CH4 instead of N2 as the detector gas supplied from the ECD detector gas supply unit 120 to the ECD 117.

[0048] Furthermore, the gas analysis apparatus according to another embodiment of the present invention may not necessarily have FID116. Figure 2 An example of this configuration is shown. Additionally, the diagram shows the configuration for... Figure 1 The components shown are identical or corresponding, and their last two reference numerals are used in the accompanying drawings, with appropriate descriptions omitted. The gas analysis apparatus shown in this figure is identical to, except that it lacks, the first chromatographic column 111, methanator 118, FID 116, FID detector gas supply unit 119, and branch adapter 126. Figure 1 The configurations shown are largely the same. However, in the following, the chromatographic column (i.e., equivalent to) connected to the ECD217 in this configuration example will be described. Figure 1 In this embodiment, the second chromatographic column 112 is referred to as the separation chromatographic column 212. In this embodiment, with... Figure 1Similarly, in the illustrated embodiment, N2 is used as the detector gas supplied from the ECD detector gas supply unit 220 to the ECD 217. Then, at the point when the sample gas flows into the inlet of the separation column 212 (which is an adsorption-type chromatographic column), the temperature control unit 224 controls the temperature inside the column oven 210 to a temperature lower than a first temperature, which is the upper limit of the temperature at which N2O is adsorbed into the separation column 212 and does not detach. Afterward, the temperature is gradually increased to a temperature higher than the first temperature, thereby concentrating the N2O before introducing it into the ECD 217. Alternatively, in this configuration example, the flow rate of the detector gas introduced into the ECD 217 can be increased at the moment when O2 elutes from the separation column 212.

[0049] Example

[0050] Using the gas analysis apparatus described in the above embodiments ( Figure 1 The apparatus shown was used to perform five consecutive analyses using atmospheric air as the sample. In this embodiment, a Jetanizer (manufactured by Activated Research Company) was used as the methanator 118, which is a jet-type methanator. Furthermore, an SH-Msi eve 5A (manufactured by Shimadzu Corporation) was used as the first column 111, and a MICROPCACKED ST (manufactured by Shinwa Chemical Co., Ltd.) was used as the second column 112. In each analysis, the temperature inside the column oven 110 was cyclically adjusted: 35°C (2 minutes) → temperature increase (40°C / minute) → 200°C → temperature increase (25°C / minute) → 230°C (3 minutes).

[0051] Figure 3 and Figure 4 The chromatogram obtained through the above analysis is shown. Figure 3 This chromatogram is generated based on the cumulative value of the detection signal from FID116. In this chromatogram, the peaks of CH4 and CO2 are indicated by arrows, and the area near the CH4 peak is magnified on the right side of the chromatogram. On the other hand, Figure 4 The chromatograms are generated based on the cumulative values ​​of the detection signals from the ECD117, with the N2O peak indicated by arrows. Furthermore, Table 1 shows the quantitative values ​​of CH4, CO2, and N2O in the samples obtained using standard curves generated from standard samples and the respective chromatograms, as well as the results of the peak area reproducibility of CH4, CO2, and N2O in the five analyses.

[0052] [Table 1]

[0053]

[0054] The quantitative values ​​obtained above are close to the values ​​of the concentrations of each component contained in the sample as assumed, and the area reproducibility is also good. Therefore, it is confirmed that the gas analysis device involved in this embodiment can appropriately analyze CH4, CO2 and N2O in the atmosphere.

[0055] [plan]

[0056] The exemplary embodiments described above are specific examples of the following solutions, which will be apparent to those skilled in the art.

[0057] (Item 1) A gas analysis apparatus according to one aspect of the present invention is a gas analysis apparatus for detecting greenhouse gases contained in a sample gas, comprising:

[0058] The carrier gas supply unit supplies nitrogen as carrier gas to two different flow paths;

[0059] The sample inlet section introduces the sample gas into the two different flow paths respectively;

[0060] The first and second chromatographic columns are respectively connected to the two different flow paths;

[0061] A hydrogen flame ionization detector is connected to the first chromatographic column;

[0062] The methanator reduces carbon dioxide flowing from the first chromatographic column and into the flame ionization detector to methane.

[0063] An electron capture detector is connected to the second chromatographic column.

[0064] In the gas analysis apparatus described in item 1, among the greenhouse gases contained in the sample gas, methane and carbon dioxide flowing from the first chromatographic column are detected by a flame ionization detector, and nitrous oxide flowing from the second chromatographic column is detected by an electron capture detector. This gas analysis apparatus is configured such that carbon dioxide flowing from the first chromatographic column and into the flame ionization detector is reduced to methane by a methanator and then detected by the detector. Therefore, carbon dioxide can be detected with high sensitivity without the need for a thermal conductivity detector. Thus, compared to the conventional method of simultaneously analyzing methane, carbon dioxide, and nitrous oxide—the main greenhouse gases—using three detectors (flame ionization detector, thermal conductivity detector, and electron capture detector), the apparatus configuration is simplified and manufacturing costs are reduced. Furthermore, conventionally, high-sensitivity detection of carbon dioxide using a thermal conductivity detector requires the use of helium as a carrier gas. However, in the gas analysis apparatus described in item 1, high-sensitivity detection of carbon dioxide can be achieved without a thermal conductivity detector, thus eliminating the need for expensive and difficult-to-obtain stable helium as a carrier gas. Furthermore, in the gas analysis apparatus involved in this invention, the high-sensitivity detection of methane and carbon dioxide in the hydrogen flame ionization detector and the high-sensitivity detection of nitrous oxide in the electron capture detector can both use relatively inexpensive nitrogen as a carrier gas, thus saving the effort of preparing multiple carrier gases and reducing the operating cost of the analysis.

[0065] (Item 2) The gas analysis apparatus involved in Item 2 is, in addition to the gas analysis apparatus involved in Item 1, further comprising:

[0066] The detector gas supply unit supplies nitrogen as the detector gas to the electron capture detector.

[0067] According to the gas analysis apparatus involved in item 2, by using nitrogen, which is relatively inexpensive and readily available, as the detector gas supplied to the electron capture detector, the cost of preparing the gas required for analysis can be suppressed.

[0068] (Item 3) The gas analysis apparatus involved in Item 3 is, in addition to the gas analysis apparatus involved in Item 1, further comprising:

[0069] The detector gas supply unit supplies detector gas to the electron capture detector;

[0070] The detector gas supply control unit controls the detector gas supply unit in such a way that the flow rate of the detector gas is increased when oxygen in the sample gas flows out of the second chromatographic column.

[0071] According to the gas analysis apparatus described in item 3, by increasing the flow rate of the detector gas supplied to the electron capture detector at the moment when oxygen flows out of the second chromatographic column, the possibility of the electron capture detector being adversely affected by the inflow of oxygen can be reduced.

[0072] (Item 4) The gas analysis device involved in Item 4 is a gas analysis device for detecting greenhouse gases contained in a sample gas, and has the following features:

[0073] Adsorption chromatographic columns;

[0074] The sample introduction section introduces the sample gas into one end of the adsorption-type chromatographic column;

[0075] An electron capture detector is connected to the other end of the adsorption column;

[0076] The detector gas supply unit supplies nitrogen as the detector gas to the electron capture detector;

[0077] Column oven, which houses the adsorption-type chromatographic column;

[0078] Temperature control unit, used to regulate the temperature inside the column oven;

[0079] The control unit controls the temperature control unit in the following manner: at the time point when the sample gas is introduced into the adsorption-type chromatographic column, the temperature inside the column oven is set to a temperature lower than a first temperature, the first temperature being the upper limit of the temperature at which nitrous oxide is adsorbed into the adsorption-type chromatographic column and does not detach; thereafter, the temperature inside the column oven is raised to a temperature above the first temperature.

[0080] In the gas analysis apparatus described in item 4, nitrous oxide, a greenhouse gas contained in the sample gas, is detected by an electron capture detector after eluting from an adsorption column. According to this gas analysis apparatus, nitrous oxide can be concentrated by an adsorption column and introduced into the electron capture detector. Therefore, even if nitrogen is used instead of the conventional Ar + 5% CH4 as the detector gas, nitrous oxide can be detected with sufficient sensitivity. Furthermore, nitrogen is relatively inexpensive and readily available, thus reducing the time and cost of preparing the gas required for analysis.

[0081] (Item 5) The gas analysis apparatus involved in Item 5 is, in addition to the gas analysis apparatus involved in Item 4, further comprising:

[0082] The detector gas supply control unit controls the detector gas supply unit in such a way that the flow rate of the detector gas is increased when oxygen in the sample gas flows out of the adsorption-type chromatographic column.

[0083] According to the gas analysis apparatus described in item 5, by increasing the flow rate of detector gas (nitrogen) supplied to the electron capture detector at the moment when oxygen flows out of the adsorption-type chromatographic column, the possibility of the electron capture detector being adversely affected by the inflow of oxygen can be reduced.

[0084] Explanation of reference numerals in the attached figures

[0085] 110 column incubator

[0086] Column 111

[0087] Column 2, 112

[0088] 113 Sample Introducing Section

[0089] 114 Automatic Sampler

[0090] 115 Carrier Gas Supply Department

[0091] 116 Hydrogen Flame Ionization Detector (FID)

[0092] 117 Electron Capture Detector (ECD)

[0093] 118 methanator

[0094] 119FID detector gas supply unit

[0095] Detector Gas Supply Section for 120ECD

[0096] 121 heater

[0097] 122 Temperature Sensor

[0098] 123 Heater Drive Unit

[0099] 124 Temperature Control Department

[0100] 125 Control Department

[0101] 126-branch adapter.

Claims

1. A gas analysis device for detecting greenhouse gases contained in a sample gas, characterized in that, have: The carrier gas supply unit supplies nitrogen as carrier gas to two different flow paths; The sample inlet section introduces the sample gas into the two different flow paths respectively; The first and second chromatographic columns are respectively connected to the two different flow paths; A hydrogen flame ionization detector is connected to the first chromatographic column; The methanator reduces carbon dioxide flowing from the first chromatographic column and into the flame ionization detector to methane. An electron capture detector is connected to the second chromatographic column.

2. The gas analysis apparatus as described in claim 1, characterized in that, Further features: The detector gas supply unit supplies nitrogen as the detector gas to the electron capture detector.

3. The gas analysis apparatus as described in claim 1, characterized in that, Further features: The detector gas supply unit supplies detector gas to the electron capture detector; The detector gas supply control unit controls the detector gas supply unit in such a way that the flow rate of the detector gas is increased when oxygen in the sample gas flows out of the second chromatographic column.

4. A gas analysis device for detecting greenhouse gases contained in a sample gas, characterized in that, have: Adsorption chromatographic columns; The sample introduction section introduces the sample gas into one end of the adsorption-type chromatographic column; An electron capture detector is connected to the other end of the adsorption column; The detector gas supply unit supplies nitrogen as the detector gas to the electron capture detector; Column oven, which houses the adsorption-type chromatographic column; Temperature control unit, used to regulate the temperature inside the column oven; The control unit controls the temperature control unit in the following manner: at the time point when the sample gas is introduced into the adsorption-type chromatographic column, the temperature inside the column oven is set to a temperature lower than a first temperature, the first temperature being the upper limit of the temperature at which nitrous oxide is adsorbed into the adsorption-type chromatographic column and does not detach; thereafter, the temperature inside the column oven is raised to a temperature above the first temperature.

5. The gas analysis apparatus as described in claim 4, characterized in that, Further features: The detector gas supply control unit controls the detector gas supply unit in such a way that the flow rate of the detector gas is increased when oxygen in the sample gas flows out of the adsorption-type chromatographic column.

Images