Session chair: Martin van der Veer, Shell (NL)
The session “Energy gases” will take place on Thursday 20 June 2019 with the following lectures:
H.01 – An ASTM international standard for the analysis of volatile silicon-containing compounds in gaseous fuels by gas chromatography with spectroscopic detection by Russell Bora, GTI (US)
Since 2016, ASTM International has been in the process of developing a standard method for the analysis of siloxanes in biomethane. This standard is currently undergoing balloting in its D03 Committee on gaseous fuels and is expected to be published in 2019. This presentation will give an overview of the methodology utilized in the standard including sample collection techniques and acceptable instrumentation. Also details on a recent GTI study will be provided, in which testing was conducted on the methodology within the proposed ASTM International standard. The goal of this study was to verify that procedures within the ASTM International standard were capable of obtaining detection limits that could meet the 0,01 mg/m3 of silicon trigger level set by the California Public Utilities Commission (CPUC) for the introduction of biomethane into a natural gas pipeline within the state of California. Included will be results of precision and accuracy tests on various organosilicon standard sources, stability tests on grab sample collection containers and materials, efficiency of sorbent materials for sorbent tube collection followed by solvent extraction, and efficacy of instrumentation including GC-MS and GC-AED. Updates of ongoing projects will also be discussed, such as the interlaboratory study (ILS) for the ASTM International standard, which will be used to determine the standard’s precision and bias.
H.02 – Analytical performance evaluation of a dynamic energy gas analyzer by Fred Kaaby, Institute for Energy Technology (NO)
The IPCC’s climate change mitigation efforts supports the use of energy gases, like biogas and hydrogen gas, to lift the heavy infrastructure in our modern society to greener levels. There are few gas analyzers that can quantify gaseous chemical compounds both for the threshold ranges specified for fuel cell hydrogen and for biogas for vehicles. Here, we present a gas chromatograph that can quantify contaminants in energy gases from parts per billion up to 100 volumetric percent without major configuration changes. We will discuss performance examples with detection limits and working ranges on common compounds found in matrices like biogas and fuel cell hydrogen gas. This gas chromatograph is capable to do stable isotope analysis by isotope ratio mass spectrometry and produce compositional data in the same run. It has part per billion detection limits on difficult species like methanol and hydrogen sulfide. It uses loop injection, but also has an available split injector and preconcentrator. The system uses preconcentration with preselected sorbents at sub-ambient temperatures and combines this with pulsed discharge helium ionization detector in fuel cell hydrogen impurity gas analysis. Preconcentration in combination with isotope ratio mass spectrometry is possible, something which are essential for dilute gas samples. A sample introduction system by use of pressurized evacuated containers demands little labour and small sample volumes and have capacities of 50 unsupervised injections of samples and standards in one sequence. Overall, the system discussed herein is very flexible for the varied performance demands of energy gases and is little labour intensive.