Gas chromatograph for analyzing catalytic reaction gas

Abstract

The utility model discloses a gas chromatograph for analyzing catalytic reaction gas, which comprises a sample introduction system, a separation system and a detector, gas to be analyzed entering a first six-way valve from the sample introduction system is divided into a front section of gas and a rear section of gas under the action of a pre-separation column; then, by switching the state of the first six-way valve, the front-section gas is conveyed to a second separation branch to be further separated and then detected by a second detector and a third detector; and the rear-section gas is conveyed to the first separation branch to be further separated and then is detected by the first detector. According to the utility model, the analysis efficiency is obviously improved, the operation process is simplified, and the analysis cost is reduced; moreover, two sample introduction modes are arranged, so that the gas inlet mode of the gas chromatograph is expanded, and the applicability of the gas chromatograph is improved.

Description

Technical Field

[0001] This utility model relates to the field of catalytic reaction gas detection technology, specifically to a gas chromatograph for analyzing catalytic reaction gases. Background Technology

[0002] In the characterization of catalysts and the analysis of products, chromatography is the core tool of analytical chemistry. The analysis of permanent gases and low-carbon hydrocarbons is mainly accomplished using gas chromatography with heated conductive cell detector (TCD) and flame ionization detector (FID).

[0003] Due to variations in catalytic equipment, the amount of gas produced can differ. During online analysis, the pressure in the tubing connecting the equipment to the chromatographic inlet is prone to fluctuations or insufficient pressure. Furthermore, the detection limits for different components vary across systems. Considering these factors, the existing analytical systems exhibit the following problems:

[0004] When using multiple detectors and multiple valve systems, such as when analyzing permanent gases and low-carbon hydrocarbons, it is necessary to configure two thermal conductivity detectors (TCD) and one flame ionization detector (FID), along with two ten-way valves and two six-way valves or even higher valve systems. Such a system greatly increases the cost of the equipment.

[0005] Second, when using an online analysis system during production, the accuracy of product analysis is affected because it cannot guarantee that the positive pressure will fully replace the quantitative loop. Utility Model Content

[0006] To address the aforementioned shortcomings of existing technologies, a gas chromatograph for analyzing catalytic reaction gases is provided, aiming to improve analytical efficiency, simplify the operation process, and reduce analytical costs.

[0007] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0008] A gas chromatograph for analyzing gases from catalytic reactions, including an injection system, a separation system, and a detector;

[0009] The separation system includes a first six-way valve connected to the injection system, a pre-separation column with both ends connected to the first six-way valve, and a first separation branch and a second separation branch connected in parallel to the first six-way valve. By switching the first six-way valve, the two ends of the pre-separation column are respectively connected to the injection system and the first separation branch, or the two ends of the pre-separation column are respectively connected to the injection system and the second separation branch. A first main separation column is provided on the first separation branch, and a first detector is connected to the end of the first separation branch. A second main separation column is provided on the second separation branch, and a second detector and a third detector are connected to the end of the second separation branch.

[0010] According to the above technical solution, the injection system includes a packed column injection port and a first carrier gas branch connected to the packed column injection port; the first carrier gas branch is connected to a first six-way valve through a pre-separation column; and an injection port connected to a manual airtight needle is provided on the packed column injection port.

[0011] According to the above technical solution, the sample introduction system includes a second six-way valve connected to an external positive pressure gas source, a metering loop connected to the second six-way valve at both ends, a first carrier gas branch connected to the second six-way valve at one end, and an external gas recovery system connected to the second six-way valve at one end; the second six-way valve and the first six-way valve are connected; by switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the first six-way valve.

[0012] According to the above technical solution, the injection system includes a second six-way valve connected to an external positive pressure gas source, a metering loop connected to the second six-way valve at both ends, a first carrier gas branch connected to the second six-way valve at one end, an external gas recovery system connected to the second six-way valve at one end, and a packed column injection port connected to the second six-way valve at one end; the second six-way valve and the first six-way valve are connected; by switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the packed column injection port;

[0013] The other end of the packed column injection port is connected to the first six-way valve, and an injection port connected to the manual airtight needle is provided on the packed column injection port; by switching the second six-way valve, the first carrier gas branch is connected to the quantitative loop, or the first carrier gas branch is connected to the packed column injection port.

[0014] According to the above technical solution, the second six-way valve includes six connection points arranged counterclockwise, A1~A6; the two ends of the quantitative loop are connected to A1 and A4, the first six-way valve or the inlet of the packed column is connected to A2, the first carrier gas branch is connected to A3, the external gas recovery system is connected to A5, and the positive pressure gas source is connected to A6.

[0015] According to the above technical solution, the first six-way valve is also provided with a second carrier gas branch;

[0016] When the first six-way valve is in single-line mode, both ends of the pre-separation column are connected to the injection system and the second separation branch; the second carrier gas branch is connected to the first separation branch.

[0017] When the first six-way valve is in the dual-line state, both ends of the pre-separation column are connected to the injection system and the first separation branch; the second carrier gas branch and the second separation branch are connected.

[0018] According to the above technical solution, the first six-way valve includes six connection points arranged counterclockwise, B1~B6; the injection system is connected to B6, the pre-separation column is connected to B1 and B5, the first separation branch is connected to B2, the second carrier gas branch is connected to B3, and the second separation branch is connected to B4.

[0019] According to the above technical solution, the first detector is a hydrogen flame ionization detector;

[0020] The second detector is a thermal conductivity cell detector; the third detector is a hydrogen methanide flame ionization detector, and the second and third detectors are connected in series; the second detector is also connected to a third carrier gas branch.

[0021] According to the above technical solution, the pre-separation column and the first main separation column are filled with polymer porous microspheres; the second main separation column is a 13X type molecular sieve column.

[0022] According to the above technical solution, the first carrier gas branch, the second carrier gas branch, and the third carrier gas branch all use high-purity argon gas; and damping columns are provided in the second and third carrier gas branches.

[0023] In this invention, catalytic reaction gas refers to a gas that is a reactant or a product in a catalytic reaction.

[0024] This utility model has the following beneficial effects:

[0025] 1. The separation system has two separation branches, which are connected to the injection system via a first six-way valve. The analyte gas entering the first six-way valve from the injection system is separated into two gas segments by the pre-separation column: H2, O2, N2, CH4, and CO in the first segment, and low-carbon hydrocarbons (C2H2, C2H4, and C2H6) in the second segment. Subsequently, by switching the state of the first six-way valve, the first segment gas is sent to the second separation branch for further separation and then detected by the second and third detectors; the second segment gas is sent to the first separation branch for further separation and then detected by the first detector.

[0026] Based on the above measures, after one injection, the gas to be analyzed is delivered to three detectors for detection by switching the first six-way valve, which significantly improves the analysis efficiency, simplifies the operation process, and reduces the analysis cost.

[0027] 2. Two injection methods are provided: online injection and manual airtight needle injection, as well as a combination of online and manual airtight needle injection; this expands the gas injection options of this gas chromatograph and improves its applicability.

[0028] 3. The second detector is a thermal conductivity detector, and the third detector is a hydrogen methanide flame ionization detector. Since the second and third detectors are connected in series to the end of the second separation branch, the second and third detectors at the end of the second separation branch can detect the detection of constant gases (H2, O2, N2, etc.) and trace gases (CH4, CO, etc.), respectively, thereby reducing equipment costs.

[0029] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it according to the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. The specific implementation methods of this utility model are given in detail in the following embodiments and their accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention.

[0031] Figure 1 This is a schematic diagram of Embodiment 1 provided by this utility model;

[0032] Figure 2 This is a schematic diagram of Embodiment 2 provided by this utility model;

[0033] Figure 3 This is a schematic diagram of Embodiment 3 provided by this utility model;

[0034] Figure 4 This utility model provides a result diagram of a single analysis of the first detector based on Embodiment 3;

[0035] Figure 5 This utility model provides a result diagram of a single analysis of the second detector based on Embodiment 3;

[0036] Figure 6 This utility model provides a result diagram of a single analysis of the third detector based on Embodiment 3;

[0037] In the diagram, 1. Pre-separation column; 2. First main separation column; 3. Second main separation column; 4. First carrier gas branch; 5. Second carrier gas branch; 6. Third carrier gas branch; 7. Damping column; 8. First detector; 9. Second detector; 10. Third detector; 11. Packed column inlet; 12. First six-way valve; 13. First separation branch; 14. Second separation branch; 15. External positive pressure gas source; 16. Second six-way valve; 17. Metering loop; 18. External gas recovery system. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-6 The principles and features of this utility model are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of this utility model. The utility model is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of this utility model will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.

[0039] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "set on" another component, it can be directly set on the other component or may also have an intervening component.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Reference Figures 1-3 As shown, the gas chromatograph for analyzing catalytic reaction gases provided by this utility model includes an injection system, a separation system, and a detector.

[0042] The gas to be analyzed in the following examples is the product gas of the photocatalytic carbon dioxide reduction reaction, mainly including CH4. 4、 C2H4, C2H6, C2H2, CO, and H2, O2, N2, etc. The product gases of the electrocatalytic reduction of carbon dioxide are also applicable to this invention. Of course, catalytic reaction gases including one or more of the above components are also applicable to this invention.

[0043] In this system, the pre-separation column 1 and the first main separation column 2 are made of porous polymer microspheres, such as Shimadzu PN packed columns, or one of HayeSep N, Poarpak-N, etc.; the second main separation column is 2m to 3m long and is filled with 13X molecular sieves with a specific surface area of ​​500m². 2 / g~700m 2 / g.

[0044] The first carrier gas branch 4, the second carrier gas branch 5, and the third carrier gas branch 6 all use high-purity argon gas; and damping columns 7 are installed on the second and third carrier gas branches.

[0045] The first detector 8 is a hydrogen flame detector; the second detector 9 is a thermal conductivity cell detector; the third detector 10 is a methanide hydrogen flame ionization detector, and the second and third detectors are connected in series; the second detector is also connected to a third carrier gas branch.

[0046] Both the hydrogen flame ionization detector and the methanation hydrogen flame ionization detector are existing structures; as shown in Figures 1-3, air and high-purity H2 are introduced into the hydrogen flame ionization detector; high-purity H2 is introduced into the converter section of the methanation hydrogen flame ionization detector, and air and high-purity H2 are introduced into the hydrogen flame ionization detector section.

[0047] Example 1

[0048] like Figure 1 As shown, the injection system includes a packed column injection port 11 and a first carrier gas branch connected to the packed column injection port; the first carrier gas branch is connected to a first six-way valve 12 through a pre-separation column; and an injection port connected to a manual airtight needle is provided on the packed column injection port.

[0049] In this embodiment, the operator injects the gas to be analyzed into the inlet of the packed column using a manual airtight needle. The gas, once inside the inlet, is then transported to the analytical system via the first carrier gas branch. This injection system is primarily designed for applications where a stable positive pressure gas source cannot be provided, preventing the accuracy of analytical results from being affected by insufficient purging of the quantitative loop.

[0050] The separation system includes a first six-way valve connected to the injection system, a pre-separation column with both ends connected to the first six-way valve, and a first separation branch 13 and a second separation branch 14 connected in parallel to the first six-way valve. By switching the first six-way valve, the two ends of the pre-separation column are connected to the injection system and the first separation branch, or to the injection system and the second separation branch, respectively. A first main separation column is provided on the first separation branch, and a first detector is connected to the end of the first separation branch. A second main separation column is provided on the second separation branch, and a second detector and a third detector are connected to the end of the second separation branch.

[0051] After the gas to be analyzed is delivered to the pre-separation column, the first six-way valve switches one section of the gas to the first separation branch and the other section to the second separation branch.

[0052] The first six-way valve is also equipped with a second carrier gas branch;

[0053] When the first six-way valve is in single-line mode, both ends of the pre-separation column are connected to the injection system and the second separation branch; the second carrier gas branch is connected to the first separation branch.

[0054] When the first six-way valve is in the dual-line state, both ends of the pre-separation column are connected to the injection system and the first separation branch; the second carrier gas branch and the second separation branch are connected.

[0055] Example 2

[0056] like Figure 2 As shown, for the analysis of catalytic reaction gases from a stable positive pressure gas source, the sample introduction system includes a second six-way valve 16 connected to an external positive pressure gas source 15, a metering loop 17 with both ends connected to the second six-way valve, a first carrier gas branch with one end connected to the second six-way valve, and an external gas recovery system 18 with one end connected to the second six-way valve; the second six-way valve and the first six-way valve are connected; by switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the first six-way valve.

[0057] In this embodiment, an external positive pressure gas source is introduced into the metering loop to fully displace it; then, the first six-way valve is switched; the gas to be analyzed in the metering loop is delivered to the separation system via the first carrier gas branch. This embodiment is suitable when the sample gas source is in a stable positive pressure state. After the gas source continuously introduces the metering loop and completes the displacement of the metering loop, the gas to be analyzed in the metering loop is delivered to the analysis system via the first carrier gas branch through the switching of the first six-way valve.

[0058] The separation system includes a first six-way valve connected to the injection system, a pre-separation column with both ends connected to the first six-way valve, and a first separation branch and a second separation branch connected in parallel to the first six-way valve. By switching the first six-way valve, the two ends of the pre-separation column are respectively connected to the injection system and the first separation branch, or connected to the injection system and the second separation branch. A first main separation column is provided on the first separation branch, and a first detector is connected to the end of the first separation branch. A second main separation column is provided on the second separation branch, and a second detector and a third detector are connected to the end of the second separation branch.

[0059] After the gas to be analyzed is delivered to the pre-separation column, the first six-way valve switches one section of the gas to the first separation branch and the other section to the second separation branch.

[0060] The first six-way valve is also equipped with a second carrier gas branch;

[0061] When the first six-way valve is in single-line mode, both ends of the pre-separation column are connected to the injection system and the second separation branch; the second carrier gas branch is connected to the first separation branch.

[0062] When the first six-way valve is in the dual-line state, both ends of the pre-separation column are connected to the injection system and the first separation branch; the second carrier gas branch and the second separation branch are connected.

[0063] Example 3

[0064] like Figure 3 As shown, this system is used for catalytic reaction gas analysis and can employ either a stable positive pressure gas source or an unstable positive pressure gas source. The injection system includes a second six-way valve connected to an external positive pressure gas source, a metering loop connected to both ends of the second six-way valve, a first carrier gas branch connected to the second six-way valve, an external gas recovery system connected to the second six-way valve, and a packed column inlet connected to the second six-way valve. The second six-way valve and the first six-way valve are connected. By switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the packed column inlet. The other end of the packed column inlet is connected to the first six-way valve, and an inlet for connection to a manual airtight needle is provided on the packed column inlet. By switching the second six-way valve, the first carrier gas branch is connected to the metering loop or to the packed column inlet.

[0065] When the second six-way valve is in single-line mode, the first carrier gas branch and the filling column inlet are directly connected, and the two ends of the metering loop are directly connected to the external positive pressure gas source and the external gas recovery system; when the second six-way valve is in double-line mode, the two ends of the metering loop are directly connected to the first carrier gas branch and the filling column inlet.

[0066] In this embodiment, both the gas inlet structures of Embodiment 1 and Embodiment 2 are set up simultaneously, wherein the filling column inlet is located between the online injection component and the separation system; depending on the pressure state of the sample gas source, the manual gas-tight needle injection mode or the online gas sampling mode is selected.

[0067] The separation system includes a first six-way valve connected to the injection system, a pre-separation column with both ends connected to the first six-way valve, and a first separation branch and a second separation branch connected in parallel to the first six-way valve. By switching the first six-way valve, the two ends of the pre-separation column are respectively connected to the injection system and the first separation branch, or connected to the injection system and the second separation branch. A first main separation column is provided on the first separation branch, and a first detector is connected to the end of the first separation branch. A second main separation column is provided on the second separation branch, and a second detector and a third detector are connected to the end of the second separation branch.

[0068] After the gas to be analyzed is delivered to the pre-separation column, the first six-way valve switches one section of the gas to the first separation branch and the other section to the second separation branch.

[0069] The first six-way valve is also equipped with a second carrier gas branch;

[0070] When the first six-way valve is in single-line mode, both ends of the pre-separation column are connected to the injection system and the second separation branch; the second carrier gas branch is connected to the first separation branch.

[0071] When the first six-way valve is in the dual-line state, both ends of the pre-separation column are connected to the injection system and the first separation branch; the second carrier gas branch and the second separation branch are connected.

[0072] In the above embodiments 1-3, as Figure 1-3 The preferred connection method of the first six-way valve is shown in the figure. The first six-way valve includes six connection points, B1 to B6; the sample injection system is connected at B6, the pre-separation column is connected at B1 and B5, the first separation branch is connected at B2, the second carrier gas branch is connected at B3, and the second separation branch is connected at B4.

[0073] In embodiments 2 and 3 above, as Figure 2-3 The preferred connection method for the first six-way valve is shown in the figure. The second six-way valve includes six connection points, A1 to A6; the two ends of the metering loop are connected to A1 and A4, the inlet of the first six-way valve or packed column is connected to A2, the first carrier gas branch is connected to A3, the external gas recovery system is connected to A5, and the positive pressure gas source is connected to A6.

[0074] In single-line mode, in the first six-way valve, B6 and B1 are connected, B2 and B3 are connected, and B4 and B5 are connected; in the second six-way valve, A6 and A1 are connected, A2 and A3 are connected, and A4 and A5 are connected.

[0075] In the dual-line state, in the first six-way valve, B1 and B2 are connected, B3 and B4 are connected, and B5 and B6 are connected; in the second six-way valve, A1 and A2 are connected, A3 and A4 are connected, and A5 and A6 are connected.

[0076] Taking Example 3 as an example, the working principle of this utility model is explained (e.g. Figure 3 (as shown)

[0077] This system consists of two automatic six-way gas valves, one packed column inlet, three chromatographic separation columns (pre-separation column, first main separation column, and second main separation column), one independent valve box (with a six-way valve inside), one thermal conductivity detector (TCD), one flame ionization detector (FID), and one flame ionization detector (FID) with a converter furnace (MTN) (i.e., methanation flame ionization detector).

[0078] During online sample injection, if the gas source can maintain a stable positive pressure, the gas source is introduced through port A6 of the second six-way valve; at this time, the second six-way valve is in single-line mode, and the positive pressure gas source completely displaces and fills the metering loop. Afterwards, the second six-way valve is switched to dual-line mode, and the gas to be analyzed in the metering loop is delivered to port B6 of the first six-way valve through the first carrier gas branch.

[0079] If the gas source cannot maintain a stable positive pressure, use a manual airtight needle for injection; the gas enters the packed column injection port through the injection port position and enters the separation system under the action of the first carrier gas branch.

[0080] When the sample passes through the second six-way valve or the injection port of the packed column, the first six-way valve is initially in a single-line state. The analyte gas entering the first six-way valve is first pre-separated into two parts by the pre-separation column: H2, O2, N2, CH4, and CO in the front part, and low-carbon hydrocarbons (C2H2, C2H4, and C2H6) in the rear part.

[0081] Under the action of the first carrier gas branch, the gas to be analyzed in the front part is delivered to the second separation branch. Then the first six-way valve switches to the dual-line state; under the action of the first carrier gas branch, the gas to be analyzed in the rear part is delivered to the first separation branch; under the action of the second carrier gas branch, the gas to be analyzed in the front part continues to flow in the second separation branch.

[0082] The H2, O2, N2, CH4, and CO in the first part are further separated by the second separation column. The constant amounts of H2, O2, and N2 are detected by the thermal conductivity detector (TCD) in the second detector and remain within the TCD. The trace amounts of CH4 and CO continue to flow downstream. CH4 and CO are sequentially fed into a hydrogen methanide flame ionization detector for detection. CH4 first passes through the converter (MTN) and is detected by the flame ionization detector (FID); CO then passes through the MTN and is converted into CH4 before being detected by the flame ionization detector (FID).

[0083] The low-carbon hydrocarbons (C2H2, C2H4, C2H6) located in the latter part are backflushed out of the pretreatment column and enter the first separation branch after the first six-way valve switches state; under the action of the second carrier gas branch. In the first separation branch, under the action of the first separation column, they are further separated into three gas segments: C2H4, C2H6, and C2H2 in sequence. These three gas segments are then sequentially passed into a flame ionization detector (FID) for detection.

[0084] Based on the above process, detection can be completed within 16 minutes with a single injection, exhibiting high sensitivity and a low detection limit, without the need to change the carrier gas (high-purity argon is used as the carrier gas in the first, second, and third carrier gas branches). The following are the detection data from the three detectors during a single injection analysis.

[0085] The data from the first detector is as follows, please refer to the appendix. Figure 4 and Table 1;

[0086] Table 1:

[0087]

[0088] The data from the second detector is as follows, please refer to the appendix. Figure 5 and Table 2;

[0089] Table 2:

[0090]

[0091] The data from the third detector is as follows, please refer to the appendix. Figure 6 and Table 3;

[0092] Table 3:

[0093]

[0094] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any way. Those skilled in the art can readily implement this utility model based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the utility model's technical solution, utilizing the disclosed technical content, are equivalent embodiments of this utility model. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of this utility model's technical solution.

Claims

1. A gas chromatograph for analyzing catalytic reaction gases, including an injection system, a separation system, and a detector; Its features are: The separation system includes a first six-way valve connected to the injection system, a pre-separation column with both ends connected to the first six-way valve, and a first separation branch and a second separation branch connected in parallel to the first six-way valve. By switching the first six-way valve, the two ends of the pre-separation column are respectively connected to the injection system and the first separation branch, or the two ends of the pre-separation column are respectively connected to the injection system and the second separation branch. A first main separation column is provided on the first separation branch, and a first detector is connected to the end of the first separation branch. A second main separation column is provided on the second separation branch, and a second detector and a third detector are connected to the end of the second separation branch.

2. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The injection system includes a packed column injection port and a first carrier gas branch connected to the packed column injection port; the first carrier gas branch is connected to a first six-way valve through a pre-separation column; and an injection port connected to a manual airtight needle is provided on the packed column injection port.

3. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The sample introduction system includes a second six-way valve connected to an external positive pressure gas source, a metering loop connected to the second six-way valve at both ends, a first carrier gas branch connected to the second six-way valve at one end, and an external gas recovery system connected to the second six-way valve at one end; the second six-way valve and the first six-way valve are connected; by switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the first six-way valve.

4. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The injection system includes a second six-way valve connected to an external positive pressure gas source, a metering loop connected to the second six-way valve at both ends, a first carrier gas branch connected to the second six-way valve at one end, an external gas recovery system connected to the second six-way valve at one end, and a packed column injection port connected to the second six-way valve at one end; the second six-way valve and the first six-way valve are connected; by switching the second six-way valve, the metering loop is connected between the external positive pressure gas source and the external gas recovery system, or between the first carrier gas branch and the packed column injection port; The other end of the packed column injection port is connected to the first six-way valve, and an injection port connected to the manual airtight needle is provided on the packed column injection port; by switching the second six-way valve, the first carrier gas branch is connected to the quantitative loop, or the first carrier gas branch is connected to the packed column injection port.

5. The gas chromatograph for analyzing catalytic reaction gases according to claim 3 or 4, characterized in that: The second six-way valve includes six connection points arranged counterclockwise, A1~A6; the two ends of the metering loop are connected to A1 and A4, the first six-way valve or packed column inlet is connected to A2, the first carrier gas branch is connected to A3, the external gas recovery system is connected to A5, and the positive pressure gas source is connected to A6.

6. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The first six-way valve is also equipped with a second carrier gas branch; When the first six-way valve is in single-line mode, both ends of the pre-separation column are connected to the injection system and the second separation branch; the second carrier gas branch is connected to the first separation branch. When the first six-way valve is in the dual-line state, both ends of the pre-separation column are connected to the injection system and the first separation branch; the second carrier gas branch and the second separation branch are connected.

7. The gas chromatograph for analyzing catalytic reaction gases according to claim 6, characterized in that: The first six-way valve includes six connection points arranged counterclockwise, B1 to B6; the injection system is connected to B6, the pre-separation column is connected to B1 and B5, the first separation branch is connected to B2, the second carrier gas branch is connected to B3, and the second separation branch is connected to B4.

8. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The first detector is a hydrogen flame ionization detector; The second detector is a thermal conductivity cell detector; the third detector is a hydrogen methanide flame ionization detector, and the second and third detectors are connected in series; the second detector is also connected to a third carrier gas branch.

9. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, characterized in that: The pre-separation column and the first main separation column are packed with porous polymer microspheres; the second main separation column is a 13X molecular sieve column.

10. The gas chromatograph for analyzing catalytic reaction gases according to claim 1, 6, or 8, characterized in that: The first, second, and third carrier gas branches all use high-purity argon gas; and damping columns are installed in the second and third carrier gas branches.

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