A sampling and analysis system

Abstract

The present invention provides a sampling and analysis system, including: a sampling gas circuit and a first, second and third detection gas circuits composed of an electronic gas circuit control module A, an electronic gas circuit control module B, an electronic gas circuit control module C, a six-way valve C, a six-way valve D, a chromatographic column A, a chromatographic column B, a chromatographic column C, a chromatographic column D, a splitter, a damper, an FID, an MSD and a TCD detector. The present invention is a sampling, sample storage and analysis system with multi-valve linkage and multi-gas circuit switching, wherein the sampling gas circuit can perform continuous sampling and stable sample storage through the linkage of the six-way valve, fully meeting the requirements of continuous sampling and multi-detector synchronous analysis in kinetic analysis experiments; a plurality of detection gas circuits that can be instantaneously switched with the sampling gas circuit can realize the parallel use and synchronous detection of TCD, FID and MSD multi-detectors, and realize the synchronous analysis of isotope transient kinetics while meeting the requirements of conventional gas-phase-gas-solid phase reaction steady-state and non-steady-state kinetic analysis.

Description

Technical field:

[0001] The invention relates to the field of gas phase and gas-solid phase reaction kinetic analysis, and in particular to a sampling and analysis system for gas phase and gas-solid phase catalytic reactions. Background technology:

[0002] Nearly 90% of chemical reactions in chemical industrial production are heterogeneous catalytic reactions. The study of the mechanism and kinetics of catalytic reactions is the basis for exploring the relationship between catalyst structure and performance, and has important theoretical and practical significance for designing highly active, highly selective and highly stable catalysts. The key to reaction mechanism research is to be able to accurately and quickly track the changes of reactants, reaction intermediates, products, etc. over time. At present, the existing reaction mechanism research methods include steady-state mechanism kinetics, non-steady-state mechanism kinetics, steady-state isotope transient mechanism kinetics, etc. In gas-phase and gas-solid-phase steady-state kinetic reactions, information such as reactant conversion rate and product yield can be obtained, which can provide basic information for reaction mechanism discrimination. In non-steady-state mechanism kinetic reactions, information on the changes of intermediate species on the catalyst surface over time can be obtained. For steady-state isotope transient mechanism kinetic analysis, information such as the coverage of different reaction species on the catalyst surface and the steps of elementary reactions can be obtained, and then the reaction mechanism and kinetic information on the surface of heterogeneous catalysts can be obtained. It is an effective method for studying the kinetics of heterogeneous catalytic reactions and plays an irreplaceable role in the study of multiphase catalytic reaction kinetics. Gas-phase and gas-solid-phase reactions are characterized by rapid reaction and susceptibility to external environmental influences, while the long chromatographic analysis time poses a great challenge to the analysis of gas-phase reaction mechanisms.

[0003] In the analysis of gas phase reaction kinetics, thermal conductivity detectors (TCD), flame ionization detectors (FID) and mass spectrometry (MS) detectors are generally used for analysis. The existing devices generally have the following problems:

[0004] (1) The FID detector can detect hydrocarbon compounds with obvious signals, but its signals for permanent gases such as O2, N2, CO2, CO, Ar, and Kr are extremely weak, which makes it impossible to make accurate judgments during kinetic analysis and reaction mechanism identification;

[0005] (2) The TCD detector has obvious signals for permanent gases such as O2, N2, CO2, CO, Ar, and Kr, but the detection signal for hydrocarbon compounds is extremely weak, so it cannot be accurately detected when the product concentration is low;

[0006] (3) The MSD detector only measures compounds and their fragment ions. It can perform good discrimination analysis on substances containing isotopes and ion fragments, but the quantitative analysis is not accurate.

[0007] (4) The traditional detector sampling system is unable to continuously sample and store the gas phase reaction products, making it impossible to accurately obtain the reaction dynamic information, especially the information on the catalyst surface species during non-steady-state and transient reactions. Therefore, it brings great trouble to the determination of reaction mechanism and kinetic analysis.

[0008] In view of the above problems, it is very necessary to develop a gas-phase and gas-solid-phase reaction kinetics analysis system and method that can perform multi-position sampling, stable storage and simultaneous multi-detector analysis. Summary of the invention:

[0009] The purpose of the present invention is to provide a multi-gas-path, multi-valve linkage sampling and analysis system for gas-phase (gas-solid-phase) reaction kinetic analysis, so as to realize continuous multi-position sampling, stable storage and multi-detector synchronous analysis of reaction products, and provide reliable experimental data and result analysis for the mechanism identification and kinetic analysis research of multi-phase catalytic reactions.

[0010] The technical solution of the present invention is as follows:

[0011] The sampling and analysis system comprises: a sampling gas circuit, an electronic gas circuit control module A, an electronic gas circuit control module B, an electronic gas circuit control module C, a six-way valve C, a six-way valve D, a chromatographic column A, a chromatographic column B, a chromatographic column C, a chromatographic column D, a splitter, a damper, an FID detector, an MSD detector and a TCD detector;

[0012] The sampling gas path is provided with a sampling port, a six-way valve A and a six-way valve B connected in series; the six-way valves A and B are each independently connected to a multi-position valve containing a quantitative loop;

[0013] The electronic gas circuit control module B is connected to the downstream chromatographic column A through the six-way valve A, and the chromatographic column A is connected to the downstream FID detector and MSD detector through the splitter; the splitter is also connected to the upstream electronic gas circuit control module C; the gas circuit connection part from the electronic gas circuit control module B to the FID and MSD detectors constitutes the first detection gas circuit, and the gas circuit connection part from the electronic gas circuit control module C to the FID and MSD detectors constitutes the second detection gas circuit; the first detection gas circuit and the sampling gas circuit form a switchable gas circuit connection relationship through the six-way valve A;

[0014] The electronic gas circuit control module A is connected to the downstream six-way valve B; the six-way valve B is connected to the downstream chromatographic column B and chromatographic column C through the six-way valve C, wherein the chromatographic column B is located downstream of the chromatographic column C; the outlet of the chromatographic column B is switchably connected to the chromatographic column D and the damping through the six-way valve D; the chromatographic column D and the damping are connected to the downstream TCD detector through the six-way valve D; the above-mentioned gas circuit connection part from the electronic gas circuit control module A to the TCD detector constitutes a third detection gas circuit; the third detection gas circuit and the sampling gas circuit constitute a switchable gas circuit connection relationship through the six-way valve B.

[0015] Furthermore, the six-way valve C simultaneously connects the inlet and outlet of the chromatographic column C and the inlet of the chromatographic column B; the electronic gas circuit control module A is connected to the outlet of the chromatographic column C through the six-way valve C to form a backflush gas circuit; the backflush gas circuit and the third detection gas circuit form a switchable gas circuit connection relationship through the six-way valve C.

[0016] Furthermore, a pre-inspection control system is provided at the inlet of the chromatographic column A; and a throttle valve is provided at the inlet of the FID detector and the MSD detector.

[0017] Furthermore, the chromatographic column A is an Al2O3 capillary column; the chromatographic column B and the chromatographic column C are porous polymer filling columns; and the chromatographic column D is a molecular sieve filling column.

[0018] Furthermore, the present invention provides a method for gas sample analysis using the above sampling and analysis system, which specifically comprises the following steps:

[0019] 1) Sampling: Control the six-way valves A and B to switch the system gas circuit to the sampling gas circuit open state; add the sample from the injection port, so that the gas sample enters the six-way valves A and B and their respective connected multi-position valves in sequence from the injection port;

[0020] 2) Synchronous analysis: Control the six-way valves A, B, and C to switch the system gas circuit to the first and third detection gas circuits open state (the sampling gas circuit is closed), and control the six-way valve D to connect the outlet of the chromatographic column B with the chromatographic column D; simultaneously start the electronic gas circuit control modules A, B, and C to allow the carrier gas to enter the first, second, and third detection gas circuits at the same time, and push the gas samples in the six-way valves A, B, and their respective connected multi-position valves into the three detection gas circuits to complete the detection and analysis;

[0021] Among them, when the gas sample in the third detection gas path enters the chromatographic column B through the six-way valve C, the six-way valve C is controlled to switch the gas path to the backflush gas path open state; when the gas sample begins to enter the TCD detector through the chromatographic column D, the six-way valve D is controlled to connect the outlet of the chromatographic column B to the damping.

[0022] The sampling and analysis system of the present invention is a sampling, sample storage and analysis system with multi-valve linkage and multi-gas path switching. Its sampling gas path can be linked with a six-way valve (and a multi-position valve) to perform continuous sampling and stable sample storage, fully meeting the requirements of continuous sampling and multi-detector synchronous analysis in kinetic analysis experiments; multiple detection gas paths that can be instantaneously switched with the sampling gas path can realize the parallel use and synchronous detection of TCD, FID, and MSD multiple detectors, and realize the synchronous analysis of isotope transient kinetics while meeting the requirements of conventional gas-phase-gas-solid phase reaction steady-state and non-steady-state kinetic analysis. Description of the drawings:

[0023] Figure 1 It is the overall gas path connection diagram of the sampling and analysis system of the present invention.

[0024] Figure 2 This is the TCD product analysis diagram of CO methanation reaction over nickel-based catalyst at 220℃.

[0025] Figure 3 This is the FID product analysis diagram of CO methanation reaction over nickel-based catalyst at 220℃.

[0026] Figure 4 This is the rate change diagram of the transient kinetic switching of the methanation reaction under 220℃ nickel-based catalyst when 50mL / min H2, 5mL / min CO, 65mL / min Ar is switched to 12.5mL / min CO, 50mL / min H2, 57.5mL / min Ar.

[0027] Figure 5 This is the transient kinetic information diagram of the methanation reaction under 220℃ nickel-based catalyst when 5mL / min CO, 20mL / min H2, 25mL / min Ar is switched to 5mL / minCO, 20mL / min D2, 25mL / min Kr.

[0028] Above Figure 1 The corresponding relationship between the markings and components is as follows: 1. 16-way multi-position valve A, 2. 16-way multi-position valve B, 3. 6-way valve B, 4. 6-way valve A, 5. 6-way valve C, 6. 6-way valve D, 7. Throttle valve B, 8. Chromatographic column B, 9. Chromatographic column C, 10. Throttle valve A, 11. Chromatographic column D, 12. Chromatographic column A, 13. Diverter, 14. Damping, 15. Electronic gas path control module A, 16. Electronic gas path control module B, 17. Electronic gas path control module C, 18. FID detector, 19. MSD detector, 20. TCD detector, 21. Inlet, 22. Front inspection control system. Specific implementation method:

[0029] In order to describe more conveniently and accurately, Figure 1In the figure, the six interfaces of each six-way valve are marked with numbers 1 to 6 in a clockwise or counterclockwise order; accordingly, they are represented by “interfaces 1 to 6” in the text description of each embodiment. Figure 1 The dotted lines and solid lines between the interfaces of the six-way valve correspond to the interface passages under different gas circuit switching states, wherein the dotted lines and solid lines between the interfaces of the six-way valves A and B correspond to the interface passages when the detection gas circuit is opened and the sampling gas circuit is opened, respectively; the dotted lines and solid lines between the interfaces of the six-way valve C correspond to the interface passages when the detection gas circuit is opened and the backflush gas circuit is opened, respectively; the dotted lines and solid lines between the interfaces of the six-way valve D correspond to the interface passages when the chromatographic column B is connected to the damping and when the chromatographic column B is connected to the chromatographic column D, respectively.

[0030] Example 1

[0031] like Figure 1 As shown, the sampling and analysis system includes: a sampling gas circuit, an electronic gas circuit control module A15, an electronic gas circuit control module B16, an electronic gas circuit control module C17, a six-way valve C5, a six-way valve D6, a chromatographic column A12, a chromatographic column B8, a chromatographic column C9, a chromatographic column D11, a splitter 13, a damper 14, a FID detector 18, an MSD detector 19 and a TCD detector 20. Among them, the chromatographic column A is an Al2O3 capillary column; the chromatographic column B and the chromatographic column C are both metal and porous polymer filling columns; the chromatographic column D is a metal and molecular sieve filling column.

[0032] The sampling gas path is provided with a sampling port 21, a six-way valve A4 and a six-way valve B3 connected in series, the six-way valve A4 is independently connected to a sixteen-way multi-position valve A1 containing a quantitative loop, and the six-way valve B3 is independently connected to a sixteen-way multi-position valve B2 containing a quantitative loop. Specifically:

[0033] The injection port 21 is connected to the interface 4 of the six-way valve A4, and the interface 3 of the six-way valve A4 is connected to the interface 2 of the six-way valve B3;

[0034] The interfaces 5 and 2 of the six-way valve A4 are respectively connected to the inlet and outlet of the sixteen-way multi-position valve A1;

[0035] The ports 3 and 6 of the six-way valve B3 are respectively connected to the inlet and outlet of the sixteen-way multi-position valve B2;

[0036] Interface 1 of the six-way valve B3 is vacant and serves as a vent.

[0037] The electronic gas circuit control module B16 is connected to the downstream chromatographic column A12 through the six-way valve A4, and the chromatographic column A12 is connected to the downstream FID detector 18 and MSD detector 19 through the splitter 13. Among them, a pre-inspection control system 22 is provided at the inlet of the chromatographic column A12 to overcome the interference during the detection process and further improve the detection stability and reliability; a throttle valve A10 is provided at the inlet of the FID detector 18, and a throttle valve B7 is provided at the inlet of the MSD detector 19. Specifically:

[0038] The electronic gas circuit control module B16 is connected to the interface 6 of the six-way valve A4, the interface 1 of the six-way valve A4 is connected to the downstream pre-inspection control system 22, the outlet of the pre-inspection control system 22 is connected to the inlet of the chromatographic column A12, and the outlet of the chromatographic column A12 is connected to the downstream FID detector 18 and MSD detector 19 through the diverter 13.

[0039] The gas path connection part from the electronic gas path control module B16 to the FID detector 18 and the MSD detector 19 constitutes the first detection gas path. The first detection gas path and the sampling gas path form a switchable gas path connection relationship through the six-way valve A4, that is, the six-way valve A4 can be used to select to open the first detection gas path (and close the sampling gas path at the same time) or to open the sampling gas path (and close the first detection gas path at the same time).

[0040] The flow divider 13 is simultaneously connected to the upstream electronic gas circuit control module C17 , forming a second detection gas circuit from the electronic gas circuit control module C17 to the FID detector 18 and the MSD detector 19 .

[0041] The electronic gas circuit control module A15 is connected to the downstream six-way valve B3; the six-way valve B3 is connected to the downstream chromatographic column B8 and the chromatographic column C9 through the six-way valve C5, wherein the chromatographic column B8 is located downstream of the chromatographic column C9; the outlet of the chromatographic column B8 is switchably connected to the chromatographic column D11 and the damper 14 through the six-way valve D6 (that is, the selective connection between the chromatographic column B8 and the chromatographic column D11 or the damper 14 can be achieved by switching the gas circuit interface of the six-way valve D6); the chromatographic column D11 and the damper 14 are connected to the downstream TCD detector 20 through the six-way valve D6. Specifically:

[0042] The electronic gas circuit control module A15 is connected to the interface 5 of the six-way valve B3;

[0043] Interface 4 of the six-way valve B3 is connected to interface 1 of the six-way valve C5;

[0044] Interfaces 6 and 3 of the six-way valve C5 are connected to the inlet and outlet of the chromatographic column C9 respectively;

[0045] The interface 2 of the six-way valve C5 is connected to the inlet of the chromatographic column B8, and the outlet of the chromatographic column B8 is connected to the interface 5 of the six-way valve D6;

[0046] Interfaces 4 and 3 of the six-way valve D6 are connected to the inlet and outlet of the chromatographic column D11 respectively;

[0047] Interfaces 6 and 1 of the six-way valve D6 are connected to the inlet and outlet of the damper 14 respectively;

[0048] Interface 2 of the six-way valve D6 is connected to the TCD detector 20 .

[0049] The gas path connection part from the electronic gas path control module A15 to the TCD detector 20 constitutes the third detection gas path. The third detection gas path and the sampling gas path form a switchable gas path connection relationship through the six-way valve B3. The six-way valve B3 can be used to choose to open the third detection gas path (and close the sampling gas path at the same time) or open the sampling gas path (and close the third detection gas path at the same time).

[0050] The electronic gas circuit control module A15 is also connected to the six-way valve C5 through a branch gas circuit, and the six-way valve C5 is simultaneously connected to the inlet and outlet of the chromatographic column C9 and the inlet of the chromatographic column B8. Specifically:

[0051] The electronic gas circuit control module A15 is connected to the interface 4 of the six-way valve C5;

[0052] The connection method between each interface of the six-way valve C5 and the chromatographic column B8 and the chromatographic column C9 is the same as the third detection gas circuit mentioned above;

[0053] Interface 5 of the six-way valve C5 is vacant and serves as a vent.

[0054] The electronic gas circuit control module A15 is connected to the gas circuit formed between the outlet of the chromatographic column C9 through the six-way valve C5 to form a backflush gas circuit; the backflush gas circuit and the third detection gas circuit are connected through the six-way valve C5 to form a switchable gas circuit connection. The six-way valve C5 can be used to select to open the third detection gas circuit (while closing the backflush gas circuit) or to open the backflush gas circuit (while closing the third detection gas circuit).

[0055] The working process of the present invention (taking the system of Example 1 as an example) is further explained below through specific detection examples.

[0056] Example 2

[0057] The test experiment used a U-shaped variable diameter reactor and a nickel-based catalyst. The reaction conditions were normal pressure and 220°C. The reaction gases were 16 mL / min H2, 4 mL / min CO, and 30 mL / min Ar.

[0058] 1) Sampling: Control the six-way valve A4 and the six-way valve B3, and switch the system gas circuit to the sampling gas circuit open state (the first and third detection gas circuits are closed); add the sample from the injection port 21, so that the gas sample enters the six-way valve A4, the sixteen-way multi-position valve A1, the six-way valve B3, and the sixteen-way multi-position valve B2 from the injection port 21 in sequence.

[0059] Specifically, the sampling gas path is opened, and under the state of stable reaction, the product gas (gas sample) enters from the injection port 21 through the interface 4 of the six-way valve A4, and then flows out from the interface 5 and enters the sixteen-way multi-position valve A1 for quantitative loop sampling; the gas sample flowing out of the sixteen-way multi-position valve A1 after sampling enters through the interface 2 of the six-way valve A4, and then flows out from the interface 3 and enters the interface 2 of the six-way valve B3, and then flows out from the interface 3 and enters the sixteen-way multi-position valve B2 for quantitative loop sampling, and the excess sampling intake gas enters the interface 6 of the six-way valve B3, and then is vented from the interface 1. In this way, the two sixteen-way multi-position valves can synchronously and sequentially complete 16 quantitative loop sampling tasks.

[0060] 2) Synchronous analysis: control the six-way valves A4, B3, and C5 to switch the system gas circuit to the open state of the first and third detection gas circuits (the sampling gas circuit is closed), and control the six-way valve D6 to connect the outlet of the chromatographic column B8 to the chromatographic column D11; at the same time, start the electronic gas circuit control modules A15, B16, and C17 to allow the carrier gas to enter the first, second, and third detection gas circuits at the same time, and push the gas samples in the six-way valves A4, B3 and their respective connected sixteen-way multi-position valves into the three detection gas circuits to complete the detection and analysis; among them, when the gas sample in the third detection gas circuit enters the chromatographic column B8 through the six-way valve C5, control the six-way valve C5 to switch the gas circuit to the open state of the backflush gas circuit (the third detection gas circuit is closed); when the gas sample begins to enter the TCD detector 20 through the chromatographic column D11, control the six-way valve D6 to connect the outlet of the chromatographic column B8 to the damping 14.

[0061] Specifically, after sampling is completed, the system gas circuit is switched to the open state of the first and third detection gas circuits, and the six-way valve D6 is controlled so that the outlet of the chromatographic column B8 is connected to the inlet of the chromatographic column D11 through the interfaces 5 and 4 of the six-way valve D6 in sequence; at the same time, the electronic gas circuit control modules A15, B16, and C17 are started to allow the carrier gas He to enter the first, second, and third detection gas circuits at the same time, pushing the gas samples in the six-way valves A4, B3 and their respectively connected sixteen-way multi-position valves into the three detection gas circuits.

[0062] In the third detection gas path, the electronic gas path control module A15 controls the carrier gas He to enter the interface 5 of the six-way valve B3, and then flows out from the interface 6 and enters the sixteen-way multi-position valve B2, pushing the gas sample in its quantitative loop to flow out (at this time, the inlet and outlet functions of the sixteen-way multi-position valve B2 are reversed, becoming the outlet and the inlet) and enter the interface 3 of the six-way valve B3, and then flows out from the interface 4 and enters the chromatographic column C9 through the interfaces 1 and 6 of the six-way valve C5 in turn for pre-separation. The separated gases (H2 / CO / N2 / O2 / CO2 / CH4 / C2 ＝o With C3 ＝o 、C4 ＝o 、C5 ＝oAfter the gas enters the chromatographic column B8, the six-way valve C5 is controlled to switch the gas circuit to the back-blowing gas circuit open state, so that the carrier gas He enters the interface 4 of the six-way valve C5 from the electronic gas circuit control module A15, and continues to enter from the outlet end of the chromatographic column C9 through the interface 3, and flows out from the inlet of the chromatographic column C9 after back-blowing the residual sample in the column, and finally vents through the joints 6 and 5 of the six-way valve C5. The gas separated by the chromatographic column B8 (H2 / CO / CO2 / CH4 / C2 ＝o After the gas passes through the interfaces 5 and 4 of the six-way valve D6, it enters the chromatographic column D11 for separation. After the gas is separated by the chromatographic column D11, the O2, H2, CO and other gases enter the TCD detector 20 for analysis through the interfaces 3 and 2 of the six-way valve D6. In a short time after the gas passes through the chromatographic column D11, the six-way valve D6 is controlled to connect the outlet of the chromatographic column B8 with the damping 14, so that the gas flowing out of the chromatographic column B8 passes through the interfaces 5 and 6 of the six-way valve D6 in sequence and enters the damping 14 for separation. After the separation, the gas (CO2, O2, N2, etc.) enters the TCD detector 20 for analysis through the interfaces 1 and 2 of the six-way valve D6.

[0063] At the same time, in the first detection gas circuit, the electronic gas circuit control module B16 controls the carrier gas He to enter the interface 6 of the six-way valve A4, and then flows out from the interface 5 and enters the sixteen-way multi-position valve A1, pushing the gas sample in its quantitative loop to flow out and enter the interface 2 of the six-way valve A4, and then flows out through the interface 1 and enters the pre-inspection control system 22 and the chromatographic column A12 in turn, and the gas sample separated by the chromatographic column A12 enters the diverter 13; at the same time, the electronic gas circuit control module C17 in the second detection gas circuit controls the carrier gas He to enter the diverter 13, and pushes the diverted gas samples to enter the FID detector 18 and the MSD detector 19 for analysis respectively.

[0064] The TCD signal of the methanogenation reaction in the steady state was obtained through the above analysis ( Figure 2 ) and FID signal ( Figure 3 ); The correction factors of H2, CO, Ar, CH4, CO2, as well as information such as CO conversion rate and methane selectivity can be calculated by the external standard method.

[0065] Example 3

[0066] The test experiment used a U-shaped variable diameter reactor and a nickel-based catalyst. The reaction conditions were 0.15MPa, 220°C, and the reaction gases were 50mL / min H2, 5mL / min CO, and 65mL / min Ar.

[0067] The sampling of product gas also adopts the synchronous sampling method of Example 1. The sampling interval is set to 2.5s. After the first two samplings are completed, the gas composition is immediately changed to: 50mL / min H2, 12.5mL / min CO and 57.5mL / min Ar. The 3rd to 15th samplings are performed at the same time to capture the change information of reactants and products over time.

[0068] The analysis steps after sampling are the same as those in Example 2.

[0069] Analyze and obtain information about the CO consumption rate, H2 consumption rate, and CH4 generation rate over time during transient changes. Figure 4 shown.

[0070] Example 4

[0071] The test experiment used a U-shaped variable diameter reactor and a nickel-based catalyst. The reaction conditions were 0.15MPa, 220°C, and the reaction gases were 20mL / min H2, 5mL / min CO, and 25mL / min Ar.

[0072] The product gas was sampled using the synchronous sampling method of Example 1, with the sampling interval set to 2.5 s. After the first two samplings were completed, the gas composition was immediately changed to: 20 mL / min D2, 5 mL / min CO, 25 mL / min Kr. The 3rd to 15th samplings were performed simultaneously to capture the information on the changes of catalyst surface species and isotope-labeled species over time.

[0073] The analysis steps after sampling are the same as those in Example 2.

[0074] Analyze and obtain information on the changes of catalyst surface species and isotope-labeled species over time during transient changes. Figure 5 shown.

Claims

1. A gas sample analysis method, characterized in that: Gas sample analysis is performed using a sampling and analysis system; wherein: The sampling and analysis system comprises: a sampling gas circuit, an electronic gas circuit control module A, an electronic gas circuit control module B, an electronic gas circuit control module C, a six-way valve C, a six-way valve D, a chromatographic column A, a chromatographic column B, a chromatographic column C, a chromatographic column D, a splitter, a damper, an FID detector, an MSD detector and a TCD detector; The sampling gas path is provided with a sampling port, a six-way valve A and a six-way valve B connected in series; the six-way valves A and B are each independently connected to a multi-position valve containing a quantitative loop; The electronic gas circuit control module B is connected to the downstream chromatographic column A through the six-way valve A, and the chromatographic column A is connected to the downstream FID detector and MSD detector through the splitter; the splitter is also connected to the upstream electronic gas circuit control module C; the gas circuit connection part from the electronic gas circuit control module B to the FID and MSD detectors constitutes a first detection gas circuit, and the gas circuit connection part from the electronic gas circuit control module C to the FID and MSD detectors constitutes a second detection gas circuit; a switchable gas circuit connection relationship is formed between the first detection gas circuit and the sampling gas circuit through the six-way valve A; The electronic gas circuit control module A is connected to the downstream six-way valve B; the six-way valve B is connected to the downstream chromatographic column B and the chromatographic column C through the six-way valve C, wherein the chromatographic column B is located downstream of the chromatographic column C; the outlet of the chromatographic column B is switchably connected to the chromatographic column D and the damper through the six-way valve D; the chromatographic column D and the damper are connected to the downstream TCD detector through the six-way valve D; the gas circuit connection part from the electronic gas circuit control module A to the TCD detector constitutes a third detection gas circuit; the third detection gas circuit and the sampling gas circuit constitute a switchable gas circuit connection relationship through the six-way valve B; The six-way valve C simultaneously connects the inlet and outlet of the chromatographic column C and the inlet of the chromatographic column B; the electronic gas circuit control module A is connected to the outlet of the chromatographic column C through the six-way valve C to form a backflush gas circuit; the backflush gas circuit and the third detection gas circuit form a switchable gas circuit connection relationship through the six-way valve C; The inlet of the chromatographic column A is provided with a pre-inspection control system; the inlets of the FID detector and the MSD detector are both provided with throttle valves; the chromatographic column A is an Al2O3 capillary column; the chromatographic columns B and C are porous polymer packed columns; the chromatographic column D is a molecular sieve packed column; The gas sample analysis specifically comprises the following steps: 1) Sampling: Control the six-way valves A and B to switch the system gas circuit to the sampling gas circuit open state; add the sample from the injection port, so that the gas sample enters the six-way valves A and B and their respective connected multi-position valves in sequence from the injection port; 2) Synchronous analysis: Control the six-way valves A, B, and C to switch the system gas circuit to the open state of the first and third detection gas circuits, close the sampling gas circuit, and control the six-way valve D to connect the outlet of the chromatographic column B with the chromatographic column D; simultaneously start the electronic gas circuit control modules A, B, and C to allow the carrier gas to enter the first, second, and third detection gas circuits at the same time, and push the gas samples in the six-way valves A, B, and their respective connected multi-position valves into the three detection gas circuits to complete the detection and analysis; Among them, when the gas sample in the third detection gas path enters the chromatographic column B through the six-way valve C, the six-way valve C is controlled to switch the gas path to the backflush gas path open state; when the gas sample begins to enter the TCD detector through the chromatographic column D, the six-way valve D is controlled to connect the outlet of the chromatographic column B to the damping.

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