Macromolecular and molecular model of coal structure

This paper presents a review of experimental data which point out that coal organic matter consists of a cross-linked macromolecular network and a complex mixture of relatively small molecules. The components of molecular phase are assumed to be clathrated in the macromolecular phase by means of electron-donor—acceptor interactions. Some parts of the molecular phase may be not extractable due to restricted orifice sizes of pores created by a macromolecular network. Determination of the content of a molecular phase in coals seems to be solved by the application of 1H-NMR free-induction decay measurements. A comparison of calculated NMR line for Wiser's representative structure with Gaussian component of the experimental NMR line for some low rank coals indicates that the above structure is a good representation for building blocks of the macromolecular phase of some coals.