Characteristics of Fundamental Combustion and NOx Emission Using Various Rank Coals

ABSTRACT Eight types of coals of different rank were selected and their fundamental combustion characteristics were examined along with the conversion of volatile nitrogen (N) to nitrogen oxides (NOx)/fuel N to NOx. The activation energy, onset temperature, and burnout temperature were obtained from the differential thermogravimetry curve and Arrhenius plot, which were derived through thermogravimetric analysis. In addition, to derive the combustion of volatile N to NOx/fuel N to NOx, the coal sample, which was pretreated at various temperatures, was burned, and the results were compared with previously derived fundamental combustion characteristics. The authors' experimental results confirmed that coal rank was highly correlated with the combustion of volatile N to NOx/fuel N to NOx. IMPLICATIONS Low-rank coals are abundant in several regions throughout the world. However, despite their quantity and relatively low market price, these low-rank coals have not been used because of a lack of existing studies...