Gas chromatographic analysis method for accurately measuring HS in coke oven gas

Abstract

The invention relates to the technical field of gas chromatographic analysis, in particular to a gas chromatographic analysis method for accurately measuring HS in coke oven gas, which comprises the following steps: firstly, starting up and preheating a prepared gas chromatographic system to ensure that two ten-way valves, two chromatographic columns and an FPD detector reach and are stabilized at a preset working temperature; injecting a quantitative coke oven gas sample into the gas path system by using a sample injection device; secondly, the sample enters a chromatographic column, and in an initial valve position state, all components in the sample begin to be preliminarily separated in the column; according to the invention, the gas chromatography ten-way valve and the chromatographic column are adopted to separate high-concentration substances in coke oven gas from H2S, and the high-concentration substances are cut out from the chromatographic column, so that the purpose of independently measuring H2S by the FPD detector is achieved, the H2S measurement is more accurate, and help is provided for efficient production of coke oven gas.

Description

Technical Field

[0001] This invention relates to the field of gas chromatography analysis technology, and more specifically, to a gas chromatography analysis method for accurately measuring H2S in coke oven gas. Background Technology

[0002] Hydrogen sulfide in coke oven gas is a harmful substance that corrodes chemical product recovery equipment and gas storage and transportation equipment. Using coke oven gas with high hydrogen sulfide content in steelmaking reduces steel quality; using it in ammonia synthesis poisons catalysts and corrodes equipment; and when used as city gas, the sulfur dioxide produced by hydrogen sulfide combustion is toxic, thus damaging environmental hygiene and affecting human health. Therefore, removing hydrogen sulfide from coke oven gas is crucial, and accurate measurement of hydrogen sulfide has become an important issue, requiring a gas chromatographic analysis method for accurately measuring H2S in coke oven gas to solve this problem. Summary of the Invention

[0003] The purpose of this invention is to provide an accurate gas chromatographic analysis method for measuring H2S in coke oven gas, so as to solve the problems mentioned in the background art. To achieve the above objectives, the present invention provides the following technical solution: a gas chromatographic analysis method for accurately measuring H2S in coke oven gas, comprising the following steps: S1. First, turn on the configured gas chromatography system and preheat it to ensure that the two 10-way valves, two chromatographic columns and one FPD detector reach and stabilize at the preset working temperature. Then, use the injection device to inject a quantitative amount of coke oven gas sample into the gas path system. S2. Next, the sample enters column 1. In the initial valve position, the components in the sample begin to separate in this column. After H2S and lighter components (such as CH4, C2H6, CO2) pass through the pre-column, but the heavy substances after H2S are still retained in the pre-column, the flow path is switched by control valve 1. S3. After the processing in step 2, the fraction containing the target components CH4, C2H6, CO2 and H2S flows out from column 1 and enters column 2. At this stage, by controlling the initial flow path setting of valve 2, the components flowing out from column 2 do not enter the detector, but are directed to a vent. S4. In column 2, the target analytes entering the column are further separated in a more refined manner. The separation order is usually: CH4→C2H6→CO2→H2S, and they are eluted sequentially according to different retention times. S5. The H2S components separated in step 4 are carried into the FPD detector by the carrier gas. S6. After the chromatographic peak of H2S has finished eluted, switch back to the initial position through control valve 2. The system is then purged with carrier gas for a period of time to ensure that there are no residual components in the pipeline and chromatographic column. At this point, one analysis cycle is completed. S7. Analysts can calculate the accurate concentration of H2S in the coke oven gas sample by comparing the peak area or peak height of H2S collected in step 5 with the standard curve. As a preferred technical solution of the present invention, in step S1, both ten-way valves are in the initial "Load" position, and the sample is carried to the inlet of column 1 by the carrier gas. As a preferred technical solution of the present invention, in step S2, the control valve 1 can switch the flow path to change the direction of the carrier gas. The carrier gas flows in reverse through the chromatographic column 1, and the heavy hydrocarbon components retained in the pre-column are purged from the system from the injection port end to prevent them from entering the subsequent system and interfering with the analysis or contaminating the chromatographic column. As a preferred embodiment of the present invention, in step S3, after all the substances preceding H2S (such as CH4, C2H6, CO2) have flowed out of the chromatographic column 2 and been vented through the vent, the H2S component is about to reach the outlet of the chromatographic column 2. As a preferred technical solution of the present invention, the FPD detector in step S5 has high selectivity and high sensitivity to sulfides. In this step, H2S components are specifically detected, and their concentration signals are converted into chromatographic peaks. The data acquisition system records the chromatographic peaks synchronously. As a preferred embodiment of the present invention, the entire system in step S6 includes the valve positions of two ten-way valves and the airflow path, which are reset to the initial state of step 1 to prepare for the next sample injection and analysis. Compared with the prior art, the present invention has the following beneficial effects: This invention is a gas chromatography analysis method for accurately measuring H2S in coke oven gas. The invention uses a 10-port gas chromatography valve and a chromatographic column to separate high-concentration substances in coke oven gas from H2S, cutting out the high-concentration substances from the chromatographic column, thereby achieving the purpose of separately measuring H2S with an FPD detector, making the measurement of H2S more accurate and helping to improve the efficiency of coke oven gas production. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a flowchart of an online measurement method for accurately measuring H2S in coke oven gas according to an embodiment of the present invention; Figure 2 This is an FPO measurement spectrum of a gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to an embodiment of the present invention. Detailed Implementation The invention will now be further described with reference to the accompanying drawings and specific embodiments: Example 1 refer to Figures 1-2 Example 1 is described, including the following steps: S1. First, turn on the configured gas chromatography system and preheat it to ensure that the two 10-way valves, two chromatographic columns and one FPD detector reach and stabilize at the preset working temperature. Then, use the injection device to inject a quantitative amount of coke oven gas sample into the gas path system. S2. Next, the sample enters column 1. In the initial valve position, the components in the sample begin to separate in this column. After H2S and lighter components (such as CH4, C2H6, CO2) pass through the pre-column, but the heavy substances after H2S are still retained in the pre-column, the flow path is switched by control valve 1. S3. After the processing in step 2, the fraction containing the target components CH4, C2H6, CO2 and H2S flows out from column 1 and enters column 2. At this stage, by controlling the initial flow path setting of valve 2, the components flowing out from column 2 do not enter the detector, but are directed to a vent. S4. In column 2, the target analytes entering the column are further separated in a more refined manner. The separation order is usually: CH4→C2H6→CO2→H2S, and they are eluted sequentially according to different retention times. S5. The H2S components separated in step 4 are carried into the FPD detector by the carrier gas. S6. After the chromatographic peak of H2S has finished eluted, switch back to the initial position through control valve 2. The system is then purged with carrier gas for a period of time to ensure that there are no residual components in the pipeline and chromatographic column. At this point, one analysis cycle is completed. S7. Analysts can calculate the accurate concentration of H2S in the coke oven gas sample by comparing the H2S chromatographic peak area or peak height collected in step 5 with the standard curve. Example 2 refer to Figure 2Example 2 further illustrates Example 1. In step S1, both ten-way valves are in the initial "Load" position, and the sample is carried to the inlet of column 1 by the carrier gas. In step S2, the control valve 1 switches the flow path to change the direction of the carrier gas, causing it to flow in reverse through column 1. This purges heavy hydrocarbon components remaining in the pre-column from the injection port to prevent them from interfering with subsequent analysis or contaminating the column. In step S3, after all substances preceding H2S (such as CH4, C2H6, CO2) have flowed out of column 2 and been vented through the vent, the H2S component is about to reach the outlet of column 2. In step S5, the FPD detector, which has high selectivity and sensitivity for sulfides, specifically detects the H2S component and converts its concentration signal into a chromatographic peak. The data acquisition system simultaneously records this peak. In step S6, the entire system, including the valve positions of the two ten-way valves and the gas flow path, is reset to the initial state of step 1, preparing for the next injection and analysis. In this embodiment, the device employs a combination of two 10-way valves, two chromatographic columns, and one FPD detector to separate substances such as CH4, C2H6, CO2, and H2S in coke oven gas, thereby achieving accurate measurement of H2S. The 2m chromatographic column 1 serves as a pre-column to backflush heavier substances after H2S, while the 2m chromatographic column 2 acts as the main separation column to separate CH4, C2H6, CO2, and H2S. Substances before the H2S peak are vented through the forward purge port 1. After H2S passes through chromatographic column 2, control valve 2 switches the gas to the FPD detector for detection. In the description of this invention, it should be noted that the terms "top," "bottom," "one side," "the other side," "front," "rear," "middle part," "inner," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas chromatographic analysis method for accurately measuring H2S in coke oven gas, characterized in that, Includes the following steps: S1. First, turn on the configured gas chromatography system and preheat it to ensure that the two 10-way valves, two chromatographic columns and one FPD detector reach and stabilize at the preset working temperature. Then, use the injection device to inject a quantitative amount of coke oven gas sample into the gas path system. S2. Next, the sample enters column 1. In the initial valve position, the components in the sample begin to separate in this column. After H2S and lighter components (such as CH4, C2H6, CO2) pass through the pre-column, but the heavy substances after H2S are still retained in the pre-column, the flow path is switched by control valve 1. S3. After the processing in step 2, the fraction containing the target components CH4, C2H6, CO2 and H2S flows out from column 1 and enters column 2. At this stage, by controlling the initial flow path setting of valve 2, the components flowing out from column 2 do not enter the detector, but are directed to a vent. S4. In column 2, the target analytes entering the column are further separated in a more refined manner. The separation order is usually: CH4→C2H6→CO2→H2S, and they are eluted sequentially according to different retention times. S5. The H2S components separated in step 4 are carried into the FPD detector by the carrier gas. S6. After the chromatographic peak of H2S has finished eluted, switch back to the initial position through control valve 2. The system is then purged with carrier gas for a period of time to ensure that there are no residual components in the pipeline and chromatographic column. At this point, one analysis cycle is completed. S7. Analysts can calculate the accurate concentration of H2S in the coke oven gas sample by comparing the peak area or peak height of H2S collected in step 5 with the standard curve.

2. The gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to claim 1, characterized in that, In step S1, both ten-way valves are in the "Load" initial position, and the sample is carried to the inlet of column 1 by the carrier gas.

3. The gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to claim 2, characterized in that, In step S2, the control valve 1 can switch the flow path to change the direction of the carrier gas. The carrier gas flows in reverse through the chromatographic column 1, which purges the heavy hydrocarbon components that remain in the pre-column from the injection port end of the system to prevent them from entering the subsequent system and interfering with the analysis or contaminating the chromatographic column.

4. The gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to claim 1, characterized in that, In step S3, after all the substances preceding H2S (such as CH4, C2H6, CO2) have flowed out of column 2 and been vented through the vent, the H2S component will soon reach the outlet of column 2.

5. The gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to claim 1, characterized in that, The FPD detector in step S5 has high selectivity and high sensitivity for sulfides. In this step, it specifically detects the H2S component and converts its concentration signal into a chromatographic peak. The data acquisition system records the chromatographic peak synchronously.

6. The gas chromatographic analysis method for accurately measuring H2S in coke oven gas according to claim 1, characterized in that, The entire system in step S6 includes the valve positions of two ten-way valves and the gas flow path, which are reset to the initial state of step 1 to prepare for the next sample injection and analysis.

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