Testing the fractional dissolution method for ashless concentrates obtained from solid fossil fuels

The paper discusses the possibility of separating the organic matter of coals and oil shales obtained by processing the initial sample with N-methylpyrollidone by the method of fractional dissolution. By the IR and NMR spectroscopy results, the separation of organic substances is assumed to occur depending on their molecular weight and structural organisation since the resulting fractions have a similar set of functional groups. A series of correlations have been identified that suggest the mechanism of interaction of N-methylpyrollidone with the organic matter of coals and shales during extraction. The dipole moment is shown to be a crirical characteristic of the solvent, which affects the degree of aromaticity of the fractions obtained for both oil shales and coal sludge.