Dey factors for formation of N_2 from low-rank coals during fixed bed pyrolysis: pyrolysis conditions and inherent minerals

摘要

Low-rank coals have been pyrolyzed in high-purity He under different conditions with a fixed bed reactor, and factors controlling N_2 formation have been examined. N_2 is the dominant product at ≥800 deg.C after almost complete release of tar-N, HCN, and NH_3. Heating rate 910-1400 deg.C/ min) affects N_2 slightly. In contrast, conversion of coal-N to N_2 increases remarkably with increasing temperature with a corresponding decrease in char-N and reaches 65-70/100 at 1200 deg.C. these data lead to a strong, reverse correlation between N_2 and char-N, which shows that char-N and/or precursors are the major source of N_2.