THE IMPACT OF MINERAL MATTER IN COAL ON ITS COMBUSTION, AND A NEW APPROACH TO THE DETERMINATION OF THE CALORIFIC VALUE OF COAL

To estimate the influence of mineral matter in coal on coal combustion , fluidized bed combustion (FBC) and pulverized coal combustion (PCC) were simulated by simple models. The theoretical calorific values of s ome hypothetical coals of different rank and mineral matter content we re calculated. The calculated calorific values of coals tend to decrea se with increasing mineral matter content. This is due to endothermic reactions of decomposition of the mineral matter as well as the heat c apacities of such minerals. The resulting combustion energy loss can b e very large. A new approach to the calculation of the calorific value of coals is also proposed.