<p>To reduce the contribution of coal mine methane to air pollution and the greenhouse effect, environmentally friendly catalytic technology has been proposed. Tri-reforming over Ni catalyst was used to utilize coal mine methane of various compositions into valuable products. The temperature and time-on-stream dependences of the conversion of feedstock and products yield were determined for the ventilation air methane (VAM, methane concentration C_CH4 ≤ 1 vol. %); coal mine/degassing methane of operating (CMM, C_CH4 = 25–60 vol. %) or abandoned (AMM, C_CH4 = 60–80 vol. %) coal mines; methane from unrelieved coal beds – virgin coal seams (CBM, C_CH4 ≥ 80 vol. %) in the temperature range from 150 to 850&#xa0;°C, atmospheric pressure and volumetric flow rate of 24,000&#xa0;h⁻¹. The results of catalytic tests were compared with the thermodynamic analysis data and optimization of process conditions was performed. It was found that methane conversion increases with growing O/C molar ratio (0.18 → 41.8) in the initial mixture and at 700&#xa0;°C it was 26, 42, 84 and 92% for the AMM (70 vol. % CH₄ + 30 vol. % air), CMM-2 (50.0 vol. % CH₄ + 50 vol. % air), CMM-1 (30.0 vol. % CH₄ + 70 vol. % air) and VAM (1.0% CH₄ + 99 vol. % air), respectively. The hydrogen concentration in the reaction products reached 30–40 vol. %. The addition of oxidizing agents (CO₂ + H₂O) to high-methane-containing coal gas leads to a significant increase in methane conversion (39 → 91%), hydrogen yield (48 → 81%) and their stability with time on stream due to optimization of an O/C molar ratio (0.42 → 1.3). Utilization of coal mine methane using the proposed catalytic technology solves a number of important problems related to the conservation of natural resources, environmental protection and the safety of coal mining, all of which are essential for advancing clean coal technologies as a key factor of green mining and sustainable development.</p> Graphical abstract <p></p>