The rate of temperature rise of a subbituminous coal during spontaneous combustion in an adiabatic device: The effect of moisture content and drying methods

This work investigates the effect of the moisture content of coal on its spontaneous ignition in oxygen (40 degrees C-140 degrees C). It has been found that the highest heating rate is achieved at a medium moisture content of similar to 7 wt% for an initial inherent moisture content of the coal before drying (in dry nitrogen at 65 degrees C) of similar to 20 wt%. This is particularly noticeable at temperatures below 80 degrees C and tends to support previous studies showing that a maximum oxidation rate occurs at such a moisture content in the same temperature range. Two drying methods have been adopted in the current work and the effects of their operating conditions on the heating rates are described.