Specific heat capacity and enthalpy of coal pyrolysis at elevated temperatures

An experimental procedure was developed enabling the specific heat capacity and enthalpy of coal pyrolysis in the instantaneous state at a given temperature to be determined. It was used to measure the thermal properties of six coals and the mineral matter at temperatures up to 1300°C. The theoretically predicted maximum of the specific heat capacity at ∼ 600°C was reproduced experimentally. However, for temperatures > 1000°C the models considerably overpredicted the experimental results. It was also found that between 300 and 800°C the decomposition of coal is endothermic, with the enthalpy of reaction ∼ 120 kJ kg−1 parent coal. Above 800°C decomposition of coal can vary from endothermic to exothermic, with the enthalpy up to 200 kJ kg−1 parent coal.