Effect of Humidity on Self-heating of a Sub-bituminous Coal under Adiabatic Conditions

A spontaneous increase in coal temperature with a possible transition into fires represents a direct hazard to coal storage and transportation. This paper evaluates the self-heating characteristics of a sub-bituminous coal under adiabatic oxidation conditions. This paper assesses the effect of relative humidity of the gas supply on the self-heating rates of coal. It is shown that an increase in the gas supply relative humidity has a marked affect on the self-heating rates of the coal. In this work the sub-bituminous coal sample undergo oxidation most rapidly when the relative humidity of the gas supply is about 70%. The effect of relative humidity decreases as oxygen concentration in the gas supply increases. A practical consequence of this finding is that improved fire safety measures should be considered during sub- bituminous coal related operations in hot and humid regions.