MOLECULAR-STRUCTURE OF REACTIVE COALS DURING OXIDATION, CARBONIZATION AND HYDROGENATION - AN INFRARED PHOTOACOUSTIC SPECTROSCOPIC AND OPTICAL MICROSCOPIC STUDY

Coals from western Canada were examined for structural changes occurring during oxidation, carbonization and hydrogenation by means of FT-IR spectroscopy, optical microscopy and chemical analysis. The coals are of Cretaceous to Eocene age, ranging in rank from subbituminous C to medium-volatile bituminous (0.42-1.47% R(o). Results indicate that the reactivity of the coals during the above mentioned processes depends on rank and petrological composition. Infrared spectroscopy is shown to be sensitive to the molecular structural changes occurring during these processes and provides a chemical basis for interpreting data from chemical analysis and optical microscopy.