Insights on the method to carry out the methane emissions inventory from abandoned underground coal mines in France

Authors: Favier, S; Gouzy, A Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2515_99

Cite As:
Favier, S & Gouzy, A 2025, 'Insights on the method to carry out the methane emissions inventory from abandoned underground coal mines in France', in S Knutsson, AB Fourie & M Tibbett (eds), Mine Closure 2025: Proceedings of the 18th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-11, https://doi.org/10.36487/ACG_repo/2515_99



Abstract:
To comply with the ‘EU Methane Strategy’ adopted by the European Commission in 2020, a new regulation on methane emission reduction in the energy sector (EU) 2024/1787 has been adopted. Accounting for 38% of methane emissions within the energy sector in 2022 (EEA 2024), the new regulation includes the monitoring of methane emissions from both active and abandoned mining activities. Such regulation requires setting up and making publicly available, an inventory of all opened and recently closed/abandoned underground coal mines in the country. For each mine, if the methane emissions of a mining component (mainly former shafts, boreholes, or galleries) are above 0.5 t CH4/year, hourly monitoring is required through the installation of measurement equipment. The new regulation raises two main challenges regarding its implementation, without currently providing any standard or technical guidance. To date, the first concerns the methodology to carry out the inventory at such a large-scale, with the need to deal with archives, historical and incomplete data for ancient, abandoned mines. The second challenge concerns the feasibility of continuously measuring emissions at a very low resolution of 0.5 t CH4/year for a large diversity of mining component configurations. To address the first challenge of the national inventory methodology, Ineris has developed an operational workflow for the French case study (Ineris 2025), inspired by the Intergovernmental Panel on Climate Change (IPCC) guidelines and the previous studies from the US Environmental Protection Agency (US EPA), that accounts for the lack of data and the diversity of mine and mining component configurations. The methodology estimates, at the basin-to-mine scale, the emissions using an approach based on the emission factor (EF). Due to the current uncertainties of this approach, the emissions estimates are qualitatively used to prioritise the mines and emissive components field verification prior to the instrumentation stage. Further improvements would allow to move to a quantitative approach.

Keywords: emissions inventory, methane, emission factor, EU 2024/1787, post-mining, coal

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