Analysis of the Composition of the C6+ Fraction of Natural Gas by Multiple Porous Layer Open Tubular Capillaries Maintained at Low Temperatures
Thomas J. Bruno, Jessica L. Burger, Tara M. Lovestead
Analysis of fuel gas (such as natural gas) for compounds with more than 6 carbon atoms (the C6+ fraction) has historically been technically complex and expensive. Hence, this is a less routine procedure that is used most often in troubleshooting rather than for day to day operations. As the sources of natural gas become more diverse, the trace constituents of the C6+ fraction are becoming more important to consider. The effects include quality issues and safety considerations such as anomalies associated with odorization. Recent advances in dynamic headspace vapor collection can be applied to this analysis and provide a faster, less complex alternative for the determination of the composition of the C6+ fraction of natural gas. Porous layer open tubular capillaries maintained at low temperatures (PLOT-cryo) formed the basis of a dynamic headspace sampling method that was developed at NIST in 2009, initially for explosives. This method has been recently advanced by the combining of multiple PLOT capillary traps into one bundle, or wafer, resulting in a device that allows the rapid trapping of relatively large amounts of analyte. In this study, natural gas analytes were collected by flowing commercial product (that is, natural gas from the laboratory mains) or a prepared surrogate gas through a chilled wafer. The analytes were then removed from the PLOT-cryo bundle by thermal desorption and flushing the wafer with helium. Gas chromatography (GC) with mass spectrometry (MS) was then used to analyze the analytes.
, Burger, J.
and Lovestead, T.
Analysis of the Composition of the C6+ Fraction of Natural Gas by Multiple Porous Layer Open Tubular Capillaries Maintained at Low Temperatures, Energy and Fuels, [online], https://doi.org/10.1021/acs.energyfuels.6b00043
(Accessed September 21, 2021)