Quantification of Fugitive Methane Emissions from Landfills: An Open Issue

Methane fugitive emissions from landfills represent a significant source of climate-altering gases emitted into the atmosphere globally. The recent Communication COM (2020) 663 reports that in the EU, 53% of anthropogenic methane emissions come from agriculture, 26% from waste, and 19% from energy. Landfills therefore represent an important emission sector, on which it is necessary to continue investing in innovation and technology to limit fugitive emissions, especially of methane. In Italy, Legislative Decree 36/2003 has imposed an obligation on landfill operators to quantitatively characterize biogas but does not indicate which technique should or can be used for monitoring. Quantifying landfill biogas flow is a complex exercise with varying degrees of uncertainty. This paper illustrates the main methods currently developed to perform this difficult task. For each method, measurement characteristics, instrumentation needed, advantages, and limitations identified for each are reported. From the analysis of the results, it can be stated that at present, there is absolutely no quantification method that is preferable to others; it is necessary to proceed with further research also considering the new instruments that technology makes available.