Characteristics of carbon monoxide production and oxidation kinetics during the decaying process of coal spontaneous combustion

• Published in: Canadian journal of chemical engineering 2018-08, Vol.96 (8), p.1752-1761
• Main Authors: Zhang, Yutao, Shi, Xueqiang, Li, Yaqing, Liu, Yurui
• Format: Article
• Language: English
• Subjects: Activation energy; Carbon monoxide; Coal; decaying process; Oxidation; oxidation kinetic activation energy; Oxygen; Oxygen content; Particle decay; Particle size; Reaction kinetics; Spontaneous combustion
• ISSN: 0008-4034; 1939-019X
• DOI: 10.1002/cjce.23119

Laboratorial experiments of coal spontaneous combustion under non‐isothermal conditions were conducted using a self‐made instrument aimed at investigating the characteristics of carbon monoxide emissions and kinetic characteristics. The impacts of coal rank, particle size, and oxygen content on the CO production during the decaying process of spontaneous combustion were studied. The experimental results demonstrated that coal particle size had a significant influence on the spontaneous combustion at high temperatures and coals of a large particle size decreased slowly in terms of the total CO production. Meanwhile, it is also found that even if the oxygen content was as low as 3 %, the oxidation reaction of coal still existed, liberating CO and heat at the same time. Therefore, stricter standards were recommended when judging whether or not a spontaneous combustion had been extinguished in gobs. Additionally, the studies on oxidation kinetics of coal implied that the activation energy was dependent both on the oxidation temperatures and coal properties. Oxidation temperatures affect the magnitude of activation energy, while coal properties impact the response of activation energy to the oxygen contents. Changing rates of CO production with temperature during the decaying process of spontaneous combustion at various oxygen contents.