文摘
A procedure for the extraction, separation and characterization of coal bitumen is described. A carboniferous coal was subjected to exhaustive (single-step) extraction with dimethylacetamide at ambient temperature. The treatment solubilized approximately 24 wt % of the organic matter. The bitumen was fractionated further and some fractions were separated into normal and branched/cyclic components. By g.c. and g.c.-m.s. n-alkanes, hopanes, benzohopanes, steranes, bicyclic sesquiterpanes, seco-hopanes, polycyclic aromatic hydrocarbons, and their alkylated homologues were identified. Number-average structure analysis was applied to the polar fractions and revealed some peculiarities of the structural units, i.e. simple molecular aggregates.