SPECIFIC-HEAT CAPACITY AND ENTHALPY OF COAL PYROLYSIS AT ELEVATED-TEMPERATURES

An experimental procedure was developed enabling the specific heat cap acity and enthalpy of coal pyrolysis in the instantaneous state at a g iven temperature to be determined. It was used to measure the thermal properties of six coals and the mineral matter at temperatures up to 1 300 degrees C. The theoretically predicted maximum of the specific hea t capacity at similar to 600 degrees C was reproduced experimentally. However, for temperatures > 1000 degrees C the models considerably ove rpredicted the experimental results. It was also found that between 30 0 and 800 degrees C the decomposition of coal is endothermic, with the enthalpy of reaction similar to 120 kJ kg(-1) parent coal. Above 800 degrees C decomposition of coal can vary from endothermic to exothermi c, with the enthalpy up to 200 kJ kg(-1) parent coal. Copyright (C) 19 96 Elsevier Science Ltd.