ABSTRACT
ABSTRACT: Temperature-programmed experiments were conducted from 20 to 450 °C in order to investigate characteristic parameters of coal spontaneous combustion at various oxidation concentrations (21%, 17%, 9%, 5%, and 3%). The experiments indicated that temperature played dominant role during the spontaneous combustion of coal. Higher temperatures would lead to larger oxidation reaction rates that represented the same trends for different oxidation concentrations. As the temperature rose, the concentrations of CO and CO2 released from spontaneous combustion were increased at the beginning and decreased after exceeding the maximums, roughly between 370 and 430 °C. What’s more, hysteresis phenomenon existed with the deduction of oxygen concentrations. So, the temperature would be higher when same CO/CO2 outputs were reached. In addition, with the increase of temperature, the production of hydrocarbons increased exponentially. However, after exceeding 370-430 °C, temperatures of C2H4 and C2H6 were decreased but the temperature of CH4 was increased continuously. The experiments also implied that temperature had negligible effect on the output of hydrocarbons at various oxidation concentrations.
