I have a question regarding the analysis of CH4 in semi-water gas
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Question: 1. Is the analysis method for CH4 in semi-water gas the same as that for CH4 in the recycle gas at the synthesis unit? How should it be analyzed? 2. In other companies within our group, the analysis showed that the methane content in semi-water gas was 1.9%. Another sample of such gas was sent to our company for analysis (after more than ten hours), and the methane content there was 4.8%. What factors could affect the methane analysis, and why is there such a large difference in the results? This post was last edited by Canghai Yili Sha on 2009-2-12 07:20.]
The analysis methods should be similar, both involving solution absorption–explosion, but the specific details are not very clear. As for such a large error, the first thing to rule out is the sampling issue: was the gas tank replaced thoroughly? Another reason is instrument calibration and operator error.
The analysis methods in the factory should be the same, all using an O-type analyzer, with solution absorption followed by explosion. It is correct that the methane content in semi-water gas is 1.9%; the person conducting the analysis should have some knowledge of the relevant processes, and they should provide a range for the analyzed values, otherwise it will lead to absurd results. The methane content in our current semi-water gas is a relatively stable value. Methane analysis is calculated by analyzing other gas components, and there are quite a number of factors that influence it. 1. Whether the analytical instrument is leaking air. 2. How much air is drawn in during an explosion. 3. The absorption capacity of the absorbent, and so on. For more details, please refer to the Analytical Technology Series published by the Small Nitrogen Fertilizer Factory.
Under normal conditions, the methane content in semi-water gas and synthetic cycle gas is different. I’m not sure what method the original poster uses; our facility employs gas chromatography, which results in very small analysis errors for the same sample. The original poster can take two more samples and have them processed at two different places simultaneously to make a comparison.
Chromatography is the best method; however, samples of different concentrations should be corrected using standard samples that are similar to them. The chromatographic column is TDX-01, with a TCD detector.
Agree with the view on the second floor. The constant analysis method for gases should be the same, using solution absorption in an Ostwald apparatus. Semi-water gas refers to the syngas produced by the fixed-bed gas generator in the gas production section ； The synthesized gas is the gas obtained after semi-water gas passes through the conversion unit, and its components are certainly different from those of the original semi-water gas.
The analysis method for CH4 in semi-water gas is different from that for CH4 in the recycle gas from the synthesis unit; when using an Ohrstedt apparatus to analyze CH4 in the recycle gas of the synthesis unit, ammonia must be removed first