Rapid method for determination of biogas composition by gas chromatography coupled to a thermal conductivity detector (GC-TCD)

The search for alternative fuel sources to replace non-renewable energy is a highly relevant topic in current research studies. Both biomethane and biohydrogen can be obtained from several anaerobic biological processes, which have some advantages over traditional energy supply chains, especially due to the ability to use various wastes and/or wastewaters as feedstock for the biogas production, which is considered a renewable fuel. These features combined with low energy inputs support the potential of these processes to play a key role in replacing fossil energy sources in the coming decades, as well as helping to avoid climate changes. Thus, it is essential to accurately determine the composition of the biogas generated in different biological processes, regardless of the application: from lab-scale studies to industrial plants. In this work, a gas chromatography set consisting of a Shimadzu/TCD GC-2030 equipped with a Supelco Carboxen 1010PLOT column was used to determine hydrogen (H2), nitrogen (N2), methane (CH4) and dioxide carbon (CO2) by a low-cost manual injection procedure". Two analytical curves (low and high ranges) were obtained for each target, which enables analysing biogas containing low and high concentrations of the targets. The validation parameters evaluated, namely, [i] linearity, working range, linear working range and sensitivity; [ii] limit of detection (LOD); [iii] limit of quantification (LOQ); and [iv] precision, expressed through repeatability and intermediate precision attested the reliability of the method for numerous applications.