Development of non-isothermal TGA-DSC for kinetics analysis of low temperature coal oxidation prior to ignition

The present work was aimed at developing a method for determining the kinetics of low temperature coal oxidation based on thermogravimetric analysis and differential scanning calorimetry (TGA-DSC). The analyses of TGA-DSC on non-isothermal oxidation of three coals at a single heating rate were carried out. The measured heat release rates and derived apparent kinetic parameters of low temperature oxidation were compared with those from the tests of basket heating methods (crossing point temperature and heat release method). The results demonstrated the equivalence of the TGA-DSC technique and the basket heating methods in measuring the heat release rate and kinetics of coal oxidation in the temperature range of about 100-150 °C. Moreover, the TGA-DSC method can also measure the kinetic parameters of coal oxidation at the temperatures from ∼150 °C to that of ignition occurring, which were shown to be different from those at the temperatures below ∼150 °C. Therefore, the TGA-DSC method developed here is promising to be applied as a cost effective technique for deriving the kinetics of low temperature oxidation to describe coal spontaneous combustion process prior to ignition.