DEVELOPMENT OF AROMATIC RING SIZE IN BITUMINOUS COALS DURING THE PLASTIC RANGE

摘要

Among many complex chemical and physical changes occurred during plastic ranges of coal, the authors focused on the changes in size of polycondensed aromatic rings since the aromatic moieties should be the main const ituents of plastic phase. Three Argonne Premium coal samples, Upper Freeport, Pittsburgh No. 8 and Illinois No.6 coals were used in the present study. Average ring size was evaluated by the solid-state NMR measurements, the results strongly indicating that the tendency of development of aromatic ring size in heat-treated char was different among three coals. It was discussed in chemical view of plastic phenomena of the coals with the assistance of the amount of transferable hydrogen in coal or char samples.