System and method for detecting content of high-content ethane by chromatography

Abstract

The invention discloses a system and method for detecting the content of high-content ethane by chromatography, the system comprises two paths of analysis systems arranged in parallel, each path of analysis system comprises a sample introduction system, a chromatographic column and a detector, each path of sample introduction system comprises a selector valve, a quantitative tube and a carrier gas tube, and the selector valves in each path of analysis system are connected through a sample gas tube; in the same analysis system, the two ends of the quantitative tube are connected with the selector valve, the carrier gas tube is connected with the selector valve, the selector valve is connected with the chromatographic column, the chromatographic column is connected with the corresponding detector, the selector valve has a first state and a second state which can be switched, and when the selector valve is switched to the first state, the detector is switched to the second state. When the selector valve is switched to the first state, gas in the sample gas pipe can be directly discharged out of the analysis system after passing through the quantitative pipe, and when the selector valve is switched to the second state, gas in the carrier gas pipe can flow to the chromatographic column through the quantitative pipe. The system can qualitatively and quantitatively detect each component in the ethane gas, can avoid the interference of high-content ethane on adjacent components, and improves the detection precision.

Description

Technical Field

[0001] The present invention relates to the technical field of ethane gas phase analysis, and in particular to a system and method for detecting high-content ethane by chromatography. Background Art

[0002] High-purity ethane is widely used in industries such as chemical engineering, metallurgy, electronics, and petroleum, as well as in scientific research, aviation, and atomic energy, as a standard gas, calibration gas, online instrument standard gas, catalyst evaluation gas, the preparation of certain specialty gas mixtures, and for research on certain mechanisms. High-purity ethane is also used as an auxiliary additive gas for dry or plasma etching in the fabrication of microelectronic components for large-scale integrated circuits. High-purity ethane, a raw material for its production, is high-content ethane in crude natural gas. High-content ethane contains impurities such as methane, propane, carbon dioxide, and oxygen. Available data indicate that the 103 gas chromatograph is typically used to analyze the content of organic impurities such as methane and propane, and the SP-2308 gas chromatograph is used to analyze oxygen content. However, due to the high content of high-content ethane, it interferes with adjacent components, resulting in low measurement accuracy. Summary of the Invention

[0003] The present invention aims to address the problem in the prior art that high ethane content interferes with adjacent components, resulting in low measurement accuracy. A system and method for detecting high ethane content by chromatography are provided. The system connects two analytical systems in parallel. Through a single injection, ethane, methane, propane, carbon monoxide, carbon dioxide, and oxygen in ethane gas can be qualitatively and quantitatively detected, thereby avoiding interference of high ethane content with adjacent components.

[0004] The present invention is achieved through the following technical solutions:

[0005] In the first aspect, the present invention provides a system for detecting high-content ethane content by chromatography, including two analysis systems arranged in parallel, each analysis system including an injection system, a chromatographic column and a detector, each injection system including a selection valve, a quantitative tube and a carrier gas tube, and the selection valves in each analysis system are connected by a sample gas tube; in the same analysis system, both ends of the quantitative tube are connected to the selection valve, the carrier gas tube is connected to the selection valve, the selection valve is connected to the chromatographic column, and the chromatographic column is connected to the corresponding detector, and the selection valve has a switchable first state and a second state. When the selection valve is switched to the first state, the gas in the sample gas tube can pass through the quantitative tube and directly discharge the analysis system. When the selection valve is switched to the second state, the gas in the carrier gas tube can flow to the chromatographic column through the quantitative tube.

[0006] In some embodiments, a pressure stabilizing system connected to the sample gas tube is also included. The pressure stabilizing system includes a sample bag, a pressure gas supply device and a container. The pressure gas supply device is connected to the inner cavity of the container through a pressure gas inlet pipe. The sample bag is located in the container, and the sample gas tube is connected to the sample bag.

[0007] In some embodiments, a pressure regulating valve is installed on the sample gas pipe to adjust the pressure of the sample gas entering the selection valve.

[0008] In some embodiments, a control valve is installed on the pressurized gas inlet pipeline to regulate the pressure in the container.

[0009] In some embodiments, a pressure gauge is installed on the lid of the container, and an input end of the pressure gauge is connected to the inner cavity of the container.

[0010] In some embodiments, the container is made of a transparent material.

[0011] In some embodiments, the lid of the container is sealed with the mouth of the container by a clamping mechanism.

[0012] In some embodiments, the detectors of the two-channel analysis system are a TCD detector and a FID detector, respectively.

[0013] In some embodiments, the chromatographic columns of the two-way analysis system are a capillary column and a packed column, respectively.

[0014] In a second aspect, the present invention provides a method for detecting high-content ethane content by chromatography, and the system for detecting high-content ethane content by chromatography according to the first aspect comprises the following steps:

[0015] Step 1: Place the sample bag in a container and connect it to the sample gas pipe. Turn on the pressure gas supply device, use the pressure gas to enter the container to pressurize the sample gas in the sample bag, switch the selection valve of the two-way analysis system to the first state, and the gas in the sample gas pipe can pass through the quantitative tube and directly discharge the analysis system, completing the sample gas injection;

[0016] Step 2: Switch the selection valve of the two-way analysis system to the second state, carry the sample gas in the quantitative tube into the chromatographic column through the carrier gas, and introduce it into the detector to analyze the gas content.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] The present invention sets two analysis systems in parallel, one analysis system adopts a TCD detector and can be used to detect oxygen, methane, carbon monoxide, carbon dioxide and ethane; the other analysis system adopts an FID detector and can be used to detect methane, ethane and propane. The two analysis systems realize separate sampling by switching the state of a selection valve, so that the ethane, methane, propane, carbon monoxide, carbon dioxide and oxygen in the ethane gas can be qualitatively and quantitatively detected through a single sampling. At the same time, a pressure stabilizing system is configured for sampling, that is, pressurized gas is introduced into a container and the sample gas in the sample bag is pressed into the selection valve through a sample gas pipe, so that constant pressure sampling can be realized, and damage to the bag body caused by local uneven force can be prevented, leakage can be prevented, the life and health of workers can be protected, and the problem of being unable to automatically introduce the sample gas into the selection valve due to insufficient pressure in the sample bag can be solved. The present invention can avoid the interference of high-content ethane on adjacent components and improve the measurement accuracy of gas components. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0020] Figure 1 Schematic diagram of the system for detecting high-content ethane content by the chromatography method of the present invention (injection state);

[0021] Figure 2 Schematic diagram of the system for detecting high ethane content by the chromatography method of the present invention (detection state).

[0022] Markings and corresponding parts names in the accompanying drawings:

[0023] 1-sample bag, 2-pressure gas supply device, 3-sample gas tube, 4-selection valve 1, 5-selection valve 2, 6-quantification tube 1, 7-quantification tube 2, 8-chromatographic column 1, 9-chromatographic column 2, 10-detector 1, 11-detector 2, 12-flow controller CAP, A-container, A1-cover, A2-clamping screw, A3-clamping seat. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0026] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0029] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0030] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces), unless otherwise clearly and specifically defined.

[0031] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0032] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0033] Please refer to Figure 1 and Figure 2 The present invention provides a system for detecting high-content ethane by chromatography, which comprises an analysis system 1 and an analysis system 2 arranged in parallel. The analysis system 1 comprises an injection system 1, a chromatographic column 18, and a detector 10. The injection system 1 comprises a selection valve 14, a quantitative tube 16, and a carrier gas tube 1. Both ends of the quantitative tube 16 are connected to the selection valve 14, the carrier gas tube 1 is connected to the selection valve 14, the selection valve 14 is connected to the chromatographic column 18, and the chromatographic column 18 is connected to the detector 10. The analysis system 2 comprises an injection system 2, a chromatographic column 29, and a detector 21. The injection system 2 comprises a selection valve 25, a quantitative tube 27, and a carrier gas tube 2. Both ends of the quantitative tube 27 are connected to the selection valve 25, the carrier gas tube 2 is connected to the selection valve 25, the selection valve 25 is connected to the chromatographic column 29, and the chromatographic column 29 is connected to the detector 211.

[0034] The selection valve 1 4 and the selection valve 2 5 are connected in parallel via the sample gas pipe 3. The selection valve 1 4 and the selection valve 2 5 are six-way valves on the gas plane, which have a carrier gas inlet, a carrier gas outlet, a sample inlet, and a sample outlet. The selection valve 1 4 has a switchable first state and a second state. When the selection valve 1 4 is switched to the first state, the gas in the sample gas pipe 3 can be directly discharged from the analysis system 1 through the quantitative pipe 1 6. When the selection valve 1 4 is switched to the second state, the gas in the carrier gas pipe 1 can flow to the chromatographic column 1 8 through the quantitative pipe 1 6. The selection valve 2 5 has a switchable first state and a second state. When the selection valve 2 5 is switched to the second state, the gas in the sample gas pipe 3 can be directly discharged from the analysis system 2 through the quantitative pipe 2 7. When the selection valve 2 5 is switched to the second state, the gas in the carrier gas pipe 2 can flow to the chromatographic column 2 9 through the quantitative pipe 2 7.

[0035] According to some embodiments of the present application, a pressure stabilizing system connected to the sample gas pipe 3 is also included. The pressure stabilizing system includes a sample bag 1, a pressure gas supply device 2 and a container A. The pressure gas supply device 2 is connected to the inner cavity of the container A via a pressure gas inlet pipeline. The sample bag 1 is located in the container A, and the sample gas pipe 3 is connected to the sample bag 1. The external pressure is evenly applied to the outer surface of the sample bag, which can quickly and labor-savingly introduce the sample gas from the sample bag into the selection valve. At the same time, the sample gas enters the selection valve evenly and stably, which is convenient for experimental use, protects the life and health of the staff, and solves the problem that the sample bag itself has low pressure and is difficult to introduce into the analytical instrument.

[0036] According to some embodiments of the present application, a pressure regulating valve is installed on the sample gas pipe 3, which is used to adjust the timely pressure of the sample gas entering the selection valve 1 4 and the selection valve 2 5. This is convenient for adapting to the needs of different analytical experiments, and the pressure of the sample gas is visible in real time, which is convenient for analysis and recording.

[0037] According to some embodiments of the present application, a control valve is installed on the pressurized gas inlet line, which is used to regulate the pressure in container A. The amount of pressurized gas entering is adjustable, which is convenient for use. At the same time, the pressure in the container is transparent and visible, ensuring that the sample bag is subjected to stable pressure and is safe and reliable.

[0038] According to some embodiments of the present application, a pressure gauge is mounted on the lid A1 of the container A, and the input end of the pressure gauge is in communication with the inner cavity of the container A. The pressure gauge allows for real-time monitoring of the air pressure within the container, and for understanding the pressure difference between the pressure within the container and the pressure in the pressurized air inlet line. Any unexpected situation can be promptly identified and resolved.

[0039] According to some embodiments of the present application, container A is made of a transparent material. Container A is transparent so that the internal conditions of the container can be directly observed. The completion of sample gas delivery in the sample bag 1 is directly visible to the naked eye, making it easy for staff to replace the sample bag or stop sampling in a timely manner.

[0040] According to some embodiments of the present application, the lid A1 of container A forms a sealed connection with the mouth of container A via multiple clamping mechanisms. The clamping mechanisms clamp the container and lid together, creating a sealed cavity within the container and preventing leakage of gas injected via the pressurized gas supply. Specifically, an annular outer edge extends outward from the top of the container, and multiple clamping mechanisms are evenly distributed around the outer edge and around the lid, pressing the lid against the outer edge.

[0041] According to some embodiments of the present application, the clamping mechanism includes a clamping screw A2 and a U-shaped clamping seat A3. The clamping seat A3 comprises two parallel baffles and a connecting block vertically fixed between the two baffles. The two baffles are respectively positioned above the lid A1 and below the annular outer edge of the mouth of the container A, and the two baffles and the connecting block form an integral structure. The middle portion of the clamping screw A2 is threadedly connected to one of the baffles and contacts the lid or the annular outer edge, pressing the lid against the annular outer edge. This clamping mechanism has a simple structure, low manufacturing cost, and is easy to implement and mass-produce.

[0042] According to some embodiments of the present application, a sealing ring is provided between the upper end surface of the annular outer edge of the mouth of the container A and the cover A1. The sealing connection through the sealing ring enhances the sealing performance of the container, further prevents leakage, and ensures reliable sample injection.

[0043] According to some embodiments of the present application, the first detector 10 is an FID detector, and the second detector 11 is a TCD detector, wherein the TCD detector is a thermal conductivity detector, and the FID detector is a hydrogen flame ionization detector.

[0044] According to some embodiments of the present application, the chromatographic column 1 8 is a capillary column, and the chromatographic column 2 9 is a packed column. A flow controller CAP12 is provided before the inlet of the capillary column.

[0045] A method for detecting high-content ethane content by chromatography provided in an embodiment of the present application, using the system for detecting high-content ethane content by chromatography described above, comprises the following steps:

[0046] Step 1, sampling process: After filling the sample bag 1 with a sufficient amount of sample gas, place the sample bag 1 in the container A, then connect one end of the sample gas outlet pipe on the sample bag 1 with the sample gas pipe 3, and then install the cover A1 on the container A; open the pressure gas supply device 2, and the pressure gas enters the container A through the pressure gas inlet pipe. When the pressure in the container A is greater than the gas pressure of the sample gas in the sample bag 1, the sample gas in the sample bag 1 is pressed out by the pressure gas in the container A, and the selection valve 1 4 and the selection valve 2 5 are switched to the first state. Figure 1As shown, the sample gas pipe 3 is connected with the quantitative tube 1 6 and the quantitative tube 2 7, and the sample gas enters the quantitative tube 1 6 and the quantitative tube 2 7 respectively. When the sample amount in the two quantitative tubes reaches the set amount, the relevant valves are closed and the gas analysis and detection are ready.

[0047] Step 2: Testing process:

[0048] refer to Figure 2 , controls selector valve 4 to switch to the second state, connecting one end of quantitative tube 6 to the carrier gas inlet and the other end of quantitative tube 6 to flow controller CAP12. Specifically, carrier helium enters selector valve 4 from carrier gas tube 1, carrying the sample gas in quantitative tube 6 into flow controller CAP12 (primarily for flow control), then into chromatographic column 8, and finally into detector 10 for gas content analysis. Detector 10 is a flame ionization detector (FID) capable of detecting methane, ethane, and propane.

[0049] Selector valve 2 (5) is controlled to switch to the second state, connecting one end of quantitative tube 2 (7) to the carrier gas inlet and the other end of quantitative tube 2 (7) to chromatographic column 2 (9). Specifically, helium carrier gas enters selector valve 2 (5) from carrier gas tube 2, carrying the sample gas in quantitative tube 2 (7) into chromatographic column 2 (9), and finally into detector 2 (11), where the gas content is analyzed. Detector 2 (11) is a TCD detector capable of detecting oxygen, methane, carbon monoxide, carbon dioxide, and ethane.

[0050] The following is a detection example, where the ethane content in the TCD detector is used as the test measurement value.

[0051] The test analysis conditions are:

[0052]

[0053] Analysis results:

[0054]

[0055] This application connects two analysis systems in parallel. One analysis system uses TCD to detect oxygen, methane, carbon monoxide, carbon dioxide, and ethane; the other analysis system uses FID to detect methane, ethane, and propane. The two analysis systems implement separate sampling by switching the state of the selection valve. Thus, with a single sampling, the qualitative and quantitative detection of ethane, methane, propane, carbon dioxide, and oxygen in ethane gas can be performed. At the same time, the technical solution of this application configures a pressure stabilization system for sampling, that is, pressurized gas is introduced into the container, and the sample gas in the sample bag is pressed into the selection valve through the sample gas pipe to prevent damage to the bag due to local uneven force, prevent leakage, protect the life and health of workers, and solve the problem of being unable to automatically introduce the sample gas into the selection valve due to insufficient pressure in the sample bag.

[0056] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for detecting high-content ethane by chromatography, characterized in that: The invention comprises two analysis systems arranged in parallel, each analysis system comprises an injection system, a chromatographic column and a detector, each injection system comprises a selection valve, a quantitative tube and a carrier gas tube, and the selection valves in each analysis system are connected through a sample gas tube; in the same analysis system, both ends of the quantitative tube are connected to the selection valve, the carrier gas tube is connected to the selection valve, the selection valve is connected to the chromatographic column, and the chromatographic column is connected to the corresponding detector, and the selection valve has a switchable first state and a second state. When the selection valve is switched to the first state, the gas in the sample gas tube can pass through the quantitative tube and directly discharge from the analysis system; when the selection valve is switched to the second state, the gas in the carrier gas tube can flow to the chromatographic column through the quantitative tube.

2. The system for detecting high-content ethane by chromatography according to claim 1, characterized in that: It also includes a pressure stabilizing system connected to the sample gas pipe, the pressure stabilizing system includes a sample bag, a pressure gas supply device and a container, the pressure gas supply device is connected to the inner cavity of the container through a pressure gas inlet pipe, the sample bag is located in the container, and the sample gas pipe is connected to the sample bag.

3. The system for detecting high ethane content by chromatography according to claim 2, characterized in that: A pressure regulating valve is installed on the sample gas pipe to adjust the pressure of the sample gas entering the selection valve.

4. The system for detecting high-content ethane by chromatography according to claim 2, characterized in that: A control valve is installed on the pressurized gas inlet pipeline to adjust the pressure in the container.

5. The system for detecting high-content ethane by chromatography according to claim 2, characterized in that: A pressure gauge is installed on the cover of the container, and an input end of the pressure gauge is communicated with the inner cavity of the container.

6. The system for detecting high ethane content by chromatography according to claim 2, characterized in that: The container is made of transparent material.

7. The system for detecting high ethane content by chromatography according to claim 2, characterized in that: The cover of the container is sealed with the mouth of the container through a clamping mechanism.

8. The system for detecting high ethane content by chromatography according to any one of claims 1 to 7, characterized in that: The detectors of the two-way analysis system are TCD detector and FID detector respectively.

9. The system for detecting high ethane content by chromatography according to claim 8, characterized in that: The chromatographic columns of the two-way analysis system are capillary column and packed column respectively.

10. A method for detecting high-content ethane content by chromatography, using the system for detecting high-content ethane content by chromatography according to claim 2, characterized in that: The following steps are involved: Step 1: Place the sample bag in a container and connect it to the sample gas pipe. Turn on the pressure gas supply device, use the pressure gas to enter the container to pressurize the sample gas in the sample bag, switch the selection valve of the two-way analysis system to the first state, and the gas in the sample gas pipe can pass through the quantitative tube and directly discharge the analysis system, completing the sample gas injection; Step 2: Switch the selection valve of the two-way analysis system to the second state, carry the sample gas in the quantitative tube into the chromatographic column through the carrier gas, and introduce it into the detector to analyze the gas content.

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