Development of Combustion Technology for Methane Emitted from Coal-Mine Ventilation Air Systems

摘要

Fugitive gas emissions from coal mining are widely known to be significant contributors to the emission of alkanes, mainly methane, to the environment. Utilization of coal-mine ventilation air methane (VAM) is a crucial mission to minimize methane emission in the atmosphere. This paper reviews current technology for mitigation and utilization of methane emissions from coal mining. Challenges and opportunities for each technology are discussed together with their benefits/disadvantages. Catalytic combustion technology is recommended as the best option due to the low and variable concentration of methane in coal-mine ventilation air, as well as its high volumetric flow. Herein, current developments in flameless combustion are discussed in detail with a few highlights on palladium-based catalyst development. The remaining uncertainties and obstacles in the development of palladium-based catalysts for VAM are also discussed. This paper highlights a few important practical aspects that necessitate further detailed investigation, such as catalyst deactivation phenomena, the stability of the catalyst under humid conditions, and the effect of coal dust on catalytic activity and stability. Notably, a pressure decrease, heat recovery/self-sustaining, and long-term deactivation are key for the successful development of VAM catalytic combustors.