CP MAS NMR-SPECTRA OF SAMPLES FROM THE ULSTER LIGNITE DEPOSITS

Cross-polarization magic angle spinning 13C spectra are presented for samples of lignite from the Ulster deposits. Some of these samples show a wealth of fine structure that is more reminiscent of lignins or peats than of brown coals, and points to the relative youth of the geological deposits. The observed carbon shifts have been assigned to carbon atoms of appropriate aromatic, carbohydrate and aliphatic structures. The aliphatic structure appears to consist of a lignin type network linking aromatic residues that carry phenolic and OCH3 groups, and a wax component in amorphous and crystalline phases. Part of the wax component could be extracted, and was also examined. The relative proportions of these constituents were measured. © 1990.