Aims and Objectives

The MEMO project focuses on increasing knowledge, experience and methods related to the detection and monitoring of fugitive methane emissions of abandoned coal mines in EU Member States.

The main objective of the project is to develop a robust methodology for establishing an unified methane emission inventory in agreement with the new EU methane regulation (EU 2024/1787). The implementation of the goal is in line with Article 6 of the RFCS Research Programme, especially for sub-points (a) and (b), that are related to develop new technologies to avoid environmental pollution, including methane leakage, of coal mines in the process of closure, formerly operating mines, and to capture, avoid, and minimize greenhouse gas (GHG) emissions, in particular methane, from coal deposits in the process of closure. Indeed, the first step of methane management is the accurate knowledge of the fugitive long-term emissions. These emissions result from the combined effect of methane desorption from abandoned coal seams and its migration toward the surface through different permeable structures, either mining components (e.g, ventilation shafts, gas collection pipes, galleries, etc) or natural structures (permeable overburden, faults and discontinuities) due to flooding, thermal and pressure gradient (Pokryszka et al., 2005).

Methane monitoring issues are the subject of already implemented projects funded by RFCS. The previous projects carried out so far have dealt with issues related to environmental and safety risk management induced by methane emission either in active coal mines (GasDrain), or during mine closure and post-closure periods (MERIDA), and its valuation as a source of clean energy from AMM and CMM (METHENERGY PLUS). These projects allowed to better understand methane emission from coal seams and its migration up to the surface. However, the leakage detection threshold of 0.5 tCH4/year/emissive component (shaft, gallery, borehole) required by the new EU regulation falls far below current measurement standard for risk management and valorization as a source of clean energy. Such low value of the threshold raised challenges regarding the sensibility of the current methane and flow sensors. Furthermore, no technical guideline currently exists in EU to carry out the inventory of AMM. The feedback from other country methane inventories, especially US inventory, highlights the challenges to deal with incomplete data for abandoned mines, and the need to develop estimation methods.

Therefore, the MEMO ambitious project, aims to meet some of these challenges by:

Defining a robust methodology for selecting the mines concerned by the inventory and establishing methane emission inventories applicable by all EU countries that accounts for the potential scarcity of available data (the starting TRL is TRL 3, aiming for TRL 6).

Defining a method for classifying the abandoned coal and lignite mines and their respective emissive components (shafts, borehole, vent, gallery, pits, etc.) according to their susceptibility to produce methane (the starting TRL is TRL 2, aiming for TRL 5).

Defining a quantification method based on emission factors estimation, tailored for the EU case study, combining, if applicable, modelling and measurements for estimating AMM (the starting TRL is TRL 2, aiming for TRL 5).

Establishing the current state of methane emission measurements applied to abandoned underground coal mines, and the feasibility to effectively estimate a CH4 flux of 0.5t/year and more (the starting TRL is TRL 3, aiming for TRL 6).

Assessing and developing measurement tools and data collection devices or networks and implementing the firsts steps to develop suitable sensors and data collection devices (the starting TRL is TRL 2, aiming for TRL 4).

Applying the developed methodology to a case study to validate its feasibility and estimate its uncertainties (TRL inapplicable).

The results of the MEMO project will be shared with the main stakeholders such as mining companies, local authorities, citizens to better carry out methane fugitive emission inventories, the first step to design efficient reduction policies to limit global warming up to 1.5°C. The results may impact and help the creation of a standard to carry out methane emission inventories for abandoned underground coal mines.

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Education and Culture Executive Agency (EACEA). Neither the European Union nor EACEA can be held responsible for them.