Influence Mechanism of Water-Soluble Sodium on Zhundong Coal Pyrolysis

An inherent water-soluble sodium-loaded coal sample was prepared using crown ether for this study. The pyrolysis process of an inherent water-soluble sodium-loaded coal sample and a water-soluble sodium compound-loaded coal sample was researched by thermogravimetric analysis (TGA). Also, the pyrolysis kinetics of the coal samples were analyzed and researched by the distributed activation energy model (DAEM). The results show that the inherent water-soluble sodium is mainly concentrated on coal particles, which further aggravates the degree of the pyrolysis reaction. The presence of sodium can promote the weight loss of coal samples in the preliminary stage of pyrolysis and the thermal condensation stage, block the escape of volatile matter during the main pyrolysis period, and inhibit the process of graphitization of char. The activation energy of pyrolysis increases with the carbon conversion rate, and the presence of sodium can reduce the activation energy under the same carbon conversion rate.