Interlaboratory Comparison to determine the majority composition of Biomethane

With the energy transition, many studies have been carried out on biogas, as it is considered a renewable energy source. For its use as fuel, a purification process is necessary, becoming biomethane, with a higher concentration of methane and calorific value. The quality control of biomethane from landfills intended different uses is established by ANP Resolution No. 886 of 2022. To comply with this Resolution, it is necessary to correctly measure the composition of the components using high-precision analytical methods. Therefore, the analytical methods were adapted so that they can determine the composition of the major components present in biomethane. A collaborative interlaboratory comparison study was conducted in order to improve and compare measurements composition results for mixtures of biomethane with major components (methane around 90%mol/mol and carbon dioxide around 1.75%mol/mol) with the purpose to assess technical competence of the participants. The study aimed to provide evidence for validated methods using alternative analytical techniques for the proposed measurement using traceable standards, and verify whether the results are in accordance with the parameters reported in the resolution. Through the results, it was possible to conclude that the methods are suitable for their intended use for methane, but for carbon dioxide, there were divergences from the reference value when it was used the portable sensor analysers.