COMPUTER-SIMULATION OF THE MOLECULAR-STRUCTURE OF BITUMINOUS COAL

Molecular modeling techniques have been used to study the three-dimensional structure and the energetics of the Given, Wiser, Solomon, and Shinn molecular models of bituminous coal. These studies demonstrate the importance of van der Waals (vdW) interactions and hydrogen bonding in the formation and stabilization of coal macromolecular structure. VdW interactions are responsible for most of the stabilization in these models, and a tendency for the relative importance of vdW interactions to increase with increasing rank is indicated. The strengths of vdW interactions for a series of aromatic and saturated ring molecules are determined and related to those in the coal structures. Physical densities and microporosities calculated for the simulated coal structures are in good agreement with those observed experimentally.