The associated molecular nature of bituminous coal

Abstract A cross-linked, three-dimensional macromolecular model has been widely accepted for the structure of coal, but there is no direct evidence to prove this model. In this paper, the conventional coal structure model is reinvestigated because of the importance of relatively strong intra- and intermolecular interactions in bituminous coal. It is reasonable to deduce that significant portions are physically associated after a study of multistep extractions, associative equilibria, the irreversibility and the dependence of coal concentration on solvent swelling, and consideration of the monophase concept. A pretreatment in coal liquefaction is also investigated on the basis of this proposed concept.