Thermodynamic characteristics of weakly caking coal oxidation and variation law of gaseous products in low oxygen concentration environment

To research the impact of oxygen consistency on the thermal dynamic characteristics and the change of gas products of weakly caking coal oxidation, differential scanning calorimetry and temperature programmed experiments were used to study, and the correlation between the intensity of heat release at distinct consistencies of oxygen and concentration of gas products was computed applying grey correlation method. The outcomes indicated that the coal low-temperature oxidation process can be categorized into three phases: speedy endothermic, slow endothermic, and exothermic. The apparent activation energy in the slow heat absorption phase exceeded the speedy endothermic stage, and the apparent activation energy in the heat release phase increased by 20.83 kJ/mol. The concentration of gas products generated at the spontaneous combustion process of coal growth when temperature went up. However, CH 4 concentration increased with the temperature rising after 120 °C. C 2 H 6 gas does not appear until 100 °C. C 2 H 4 gas appeared after 90 °C. At various O 2 consistencies, the correlation between exothermic intensity and CO 2 remained the largest, the correlation between exothermic intensity and CO and CH 4 was larger at lower oxygen consistencies. As concentration of oxygen increased, the correlation between exothermic intensity and C 2 H 4 and C 2 H 6 increased first and then decreased.