Supramolecular Structure of Coals of the Metamorphism Series

The molecular structure characteristics of brown and hard coals of the metamorphism series were determined using IR spectroscopy. Based on the data of X-ray diffraction analysis and the kinetics of swelling in solvents, their supramolecular structure and the mechanism of molecular diffusion in the organic mass of coals were studied. Relationships between the supramolecular structure and molecular composition indices were established, and the structure evolution in the series of coal metamorphism was considered. It was found that tetrahydrofuran and quinoline molecules penetrated into the bulk of the organic mass of most coals by molecular Fickian diffusion complicated by steric hindrances of the microporous structure.