An assessment of mine methane mitigation and utilisation technologies

Abstract

Fugitive methane, emitted from coalmines around the world, represents approximately 8% of the world's anthropogenic methane emissions that constitute a 17% contribution to total anthropogenic greenhouse gas emissions. Coal mine methane is a general description for all methane released prior to, during and after mining operations. As such, there is considerable variability in flow rate and composition of the various gas emissions during mining operations. At a typical gassy mine methane is emitted in three streams: (1) mine ventilation air (0.1–1% CH 4), (2) gas drained from the seam before mining (60–95% CH 4), and (3) gas drained from worked areas of the mine, e.g. goafs, (30–95% CH 4). Ventilation air methane contributes approximately 64% of coalmine methane emissions from typical gassy coal mines. The existing and developing technologies for coal mine methane mitigation and utilisation are classified, with a discussion of the features of different technologies to identify potential technical issues for each technology when implemented at a mine site and to identify the best options for mine site applications. A technical assessment of these technologies for use at a Queensland coal mine is presented, with a preliminary economic assessment of some technologies that were determined to be technically feasible. The assessment is carried out on the basis of real mine methane emission data over about a 1-year time frame.