What analytical method was used?
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For routine sampling and analysis of C4 compounds after hydrogenation, a chromatograph is used to heat them into a gaseous state in order to determine the composition of all components; the hydrogen content is not displayed； Yesterday, sampling was carried out at the same location using an air pocket, with the aim of analyzing the hydrogen content in the gas. The hydrogen content determined to be 59.1% by weight; it seems hard to believe that such a high level of hydrogen was detected ； Similarly, for gas analysis, different analytical methods lead to significant variations in the results; which analytical data should be trusted?
This post was last edited by qugd on 2015-6-18 at 21:39; the chromatograph was modified to use helium as the carrier gas for a full analysis, which allows for the detection of both hydrocarbon components and hydrogen components. It is estimated that you used hydrogen as the carrier gas for hydrocarbon composition analysis, which is why there are no results for the hydrogen composition analysis. Then you should use the external standard method for analysis; the other components can be quantified directly. Or, only the liquid phase was sampled, and the gaseous phase present in the upper layer at equilibrium was released from the sampler. In the latter case, it is recommended to install a balance tank at the sampling point; after balancing, samples of the liquid and gas phases should be taken separately and analyzed individually, with the results then combined for further calculation. This type of analysis will be more rigorous and complex. Alternatively, one can refer to the sample handling methods used in online chromatography: a vaporization pressure reducing valve is installed at the sampling point; after sampling with an air bag, the bag is reheated and brought to equilibrium in the laboratory before analysis.
The samples you collected may contain a gas phase and a liquid phase; the gas phase has a high hydrogen content while the liquid phase has a low hydrogen content