Relevance of structure, fragmentation and reactivity of coal to combustion and oxy-combustion

摘要

The nature and extent of the microstructural changes of coal upon oxidation under conditions typical of combustion systems, and the relation between microstructure and reactivity towards oxygen and carbon dioxide have been extensively addressed. The first major changes in morphology, structure and chemical composition of the solid fuel occur in the early instances of combustion/gasification processes, during heat up and devolatilization. At this stage particles can be broken into smaller fragments as a consequence of thermal stress and pressure generated by volatiles release. This phenomenon, regarded to as primary fragmentation, is considered responsible of important changes in the fuel particle size distribution within reactors.