Underground pilot demonstrator for ventilation air methane oxidation: Feasibility and safety under mining conditions

Methane, along with carbon dioxide, is one of the principal greenhouse gases responsible for climate change. Each year, substantial amounts of methane are released from underground coal mines. New regulations require mining companies to reduce these emissions. This paper presents a pilot underground installation for the catalytic oxidation of methane from mine ventilation air with low methane content (VAM), combined with on-site utilisation of the released heat for cooling at the working face. The study focuses on defining the operating range of the system and evaluating its safety under experimental underground conditions. The pilot installation operated at methane concentrations of 0.1–1.0 vol.% and gas flow rates up to 2400 m³ x h⁻¹, with catalyst temperatures maintained in the autothermal operating range of approximately 450–550°C. Unlike conventional surface-based VAM systems, the proposed underground configuration enables direct on-site utilisation of the recovered heat for mine cooling, reducing energy losses associated with long-distance heat transport. The installation was tested regarding exhaust gas composition, potential formation of harmful by-products, changes in oxygen concentration, and surface temperatures of components accessible to personnel. Measurements were carried out during controlled pilot operation at different methane concentrations. Under the tested conditions, methane conversion reached 85–98%. No hazardous levels of CO or NOₓ were detected. Surface temperatures of accessible parts of the system stayed below levels that could cause any burns. These results demonstrate that catalytic VAM oxidation can be performed safely in an underground pilot installation and that the concept is technically feasible.