Theoretical and Experimental Insight into Coal Structure: Establishing a Chemical Model for Yuzhou Lignite

Because of their complex supermolecular structure, coal structures are challenging. We have tried to establish a novel method to construct a three-dimensional chemical model with proper reactivity for Yuzhou lignite using experimental and theoretical methods. Structural units of the Yuzhou lignite were built using elemental analysis, infrared analysis, 13C nuclear magnetic resonance spectra, and density functional theory calculation. A three-dimensional chemical model was built in a periodic box in order to rationalize intra- and intermolecular interactions. To confirm the validity of the proposed model, we compared bond cracking pathways occurring during pyrolysis experiments using thermal gravimetric analysis and numerical dynamic reactive simulations employing the ReaxFF of thermal cracking of the model that we proposed. Experimental and numerical simulations results agreed, validating our building procedure. Therefore, this model could reflect both the basic structural characteristics and the thermal reactivity of Yuzhou lignite.