Coal burning, interrelated processes

A simplified model of PC combustion includes the following sequence of events (I) on entering the furnace, a PC particle is heated rapidly, driving off the volatile components and leaving a char particle (2) the volatile components burn independently of the coal particle and (3) on completion of volatiles combustion, the remaining char particle burns. Whue this simple sequence may be generally correct, PC combustion is an extremely complex process involving many interrelated physical and chemical processes. 

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