For coal conversion using pyrolysis or hydrogenation the prediction of the very complex processing behavior of coal is of prime importance. A first approach can be given by a systematic examination of the micropetrography of solid residues. Thereby, a threefold classification could be drawn, distinguishing between components of the original macerals, the coked material and the inorganic residues. In addition to this generally nomenclature, the components can also serve as indicators for the process course and efficiency, and can provide possible indications for process optimization.