Thermogravimetric analysis of pyrolysis characteristics of conventional pulverized coal

An investigation combining thermogravimetric analysis/differential scanning calorimeter technique and a fundamental study of coal characteristics was conducted on different coal samples sourced from Chinese coalfields. This analysis investigated the impact of several factors, including heating rate, particle size, and the propensity of coal for spontaneous combustion, on the pyrolysis process of coal. In addition, the characteristic temperature points corresponding to each stage of the experimental process were defined. Thermogravimetric analysis study of coal samples indicates that heating rate, particle size, and coal spontaneous combustion propensity significantly influence the pyrolysis process, as reflected by variations in the thermogravimetric/differential thermogravimetric curves under different conditions. The weight loss rate increases when the heating rate decreases/particle size decreases/spontaneous ignition propensity increases. Kinetic analysis shows that the activation energy is positively correlated with the heating rate. The calculated findings reveal that the activation energy diminishes when the heating rate decreases/particle size decreases/spontaneous ignition propensity increases, which is in accordance with the experimental results. Our results suggest that the activation energy can be available to assess the spontaneous combustion of coal. This study not only deepens the understanding of the thermal reactivity of coal under varying conditions but also offers important insights for early warning and risk evaluation in coal mining and storage operations.