On-line gas analysis for gasification units
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This post was last edited by lflsedin on 2014-12-24 21:10. Dear teachers, could we discuss here the methods used for online detection and analysis of gaseous substances such as carbon monoxide, carbon dioxide, hydrogen, methane, hydrogen sulfide, sulfur oxides, nitrogen, argon, etc., in your company’s gasification units? Thank you!
Carbon monoxide, carbon dioxide, hydrogen, methane, and nitrogen can all be effectively detected using gas chromatography, mass spectrometry, and infrared spectroscopy. However, the methane content is relatively low; in normalized analysis, fluctuations in other components can affect the accuracy of measurement, so trace analysis of methane is generally conducted separately. This post was last edited by shanxg on 2009-2-10 08:49]
Carbon monoxide, carbon dioxide, hydrogen, methane, and nitrogen are detected using gas chromatography; it takes about 9 minutes to analyze a set of data with this method, whereas it takes around 18 seconds using mass spectrometry. Mass spectrometry has the advantages of rapid response and accurate analysis. For online, real-time, quantitative analysis of syngas, many plants use mass spectrometers. As far as I know, the mass spectrometers produced by the British company Hiden enable online, rapid quantitative analysis, and they have offices in Beijing and Shanghai. An important aspect of analyzing methane concentration is determining the temperature inside the furnace; the higher the temperature, the lower the methane content. This post was last edited by shanxg on 2009-2-10 08:50]
It is still not easy to carry out online monitoring of raw gas that has not been cooled or depressurized using current analysis techniques, because even with chromatographic analysis, it takes about 9 minutes to process a set of data.
It is a gas chromatograph, because in the shell gasification process, it is controlled by valves 58 and 59 in unit 16, allowing for online analysis. The syngas passes through unit 15, is relatively clean, with a very low solid content, so a gas chromatograph is suitable for this purpose
Gas chromatography can be used for analysis, but the accuracy of online analysis still needs to be improved; often, there is a significant difference between the data obtained from online analysis and those from sampling analysis, and the normalization of the online analysis data cannot equal 1.
“I’m not quite sure what it means that “online normalization cannot equal 1”. Could you please explain it? I’m new to online analysis, and I’m also having trouble understanding the differences between online data and sampled data. Thank you