TY - JOUR A1 - Wu, D. A1 - Schmidt, Martin A1 - Huang, X. A1 - Verplaesten, F. T1 - Self-ignition and smoldering characteristics of coal dust accumulations in O2/N2 and O2/CO2 atmospheres T2 - Proceedings of the Combustion Institute 36 (2017) N2 - The self-ignition of coal dust deposits and its subsequent smoldering combustion pose a high fire hazard to oxy-fuel power systems which burn fuels using pure oxygen for the sake of carbon capture and storage. The increasing risk of explosion in the gas-phase and self-ignition in the solid-phase for an oxygen enhanced combustion environment has not been well studied yet. In this work, the heterogeneous reactions of a bituminous coal dust are investigated by using a novel hot-basket apparatus with an emphasis on the roles of O2 and diluent gas in chemisorption and smoldering. Experiments show that increasing O2 mole fraction accelerates both self-ignition and the following smoldering combustion. On the other hand, the presence of CO2 increases the ignition temperature and reduces the maximum smoldering temperature. However, the promotion in the fire and explosion risk by elevating O2 mole fraction is substantially stronger than the retardation effected by presence of CO2. The emission-gas measurements show that the CO to CO2 ratio increases significantly after self-ignition, and CH4 counts for 1–8% of the total carbon emission. This research may help improve the understanding of heterogeneous coal combustion and the fire safety in oxy-fuel power systems. KW - Oxy-fuel cobustion KW - Fire hazard KW - FTIR KW - CO/CO2 ratio KW - CH4 PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/39927 AN - OPUS4-39927 SN - 1540-7489 SN - 1873-2704 VL - 36 IS - 2 SP - 3195 EP - 3202 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany