Mitigation of methane emissions from coal mine ventilation air: an update

摘要

Control of methane emissions from mine ventilation systems has been a challenging goal because of the magnitude of typical airflows coupled with very low methane concentrations. The authors evaluated the technical and economic feasibility of several emerging systems that may accept up to 100 percent of the flow from a gassy underground coal mine ventilation shaft, oxidize the entrained methane, and produce marketable energy. This paper discusses flow-reversal oxidizers that provide heat for producing thermal or electric energy, lean-fueled combustion turbines, and a hybrid waste coal and methane power plant. The paper also covers research into methane concentration techniques and the use of ventilation air methane as combustion air for a variety of prime movers. When ventilation shafts emit methane concentrations approaching 1.0 percent, energy prices are high, and revenues from greenhouse gas emission reduction offsets are available, it will be possible to operate a profitable energy plant fueled with ventilation air methane.