-Coals with carbon contents of 60-80wt% daf were pyrolyzed using a Curie point pyrolyzer at 764-1, 040°C for 5s. In order to explain the effect of coal ranks on product distribution, the cleaving energies of the unit structures of coal were estimated by a reaction coordinate analysis based on the molecular orbital calculation using the WinMOPAC program. The coal pyrolysis reactivity and product distributions were then discussed on the basis of the cleaving energies of the unit structures.
