NMR CHARACTERIZATION OF EXTRACTS PRODUCED BY DISSOLUTION OF UK COALS IN HYDROGENATED ANTHRACENE OIL AND IN SUPERCRITICAL TOLUENE

Based on data from nmr spectra and elemental analyses, structural parameters were calculated for the extraction of three samples of UK coals by supercritical toluene and by hydrogenated anthracene oil (HAO). The asphaltenes from HAO extraction were more aromatic and contained a higher amount of methylene bridges. The supercritical toluene extracts had more alkyl substitution and contained a higher sulphur content. The toluene molecules seemed to promote some rupturing of SS bonds and alkyl chains with transfer of hydrogen from hydroaromatic centres within the coal structure to stabilize the radicals formed. © 1990.