Solid state 13C n.m.r. dipolar dephasing study of Canadian coals

Abstract A diverse set of 19 predominantly Albertan coals ranging in rank from lignite to semianthracite have been analysed in detail with respect to their carbon functional group distributions as determined by 13 C solid state nuclear magnetic resonance dipolar dephasing experiments. Detailed aliphatic and aromatic protonated and non-protonated carbon distributions were obtained from complete multiple delay time analyses. Variables investigated included rank (%carbon), carbon aromaticity, hydrogen aromaticity, mol%oxygen, mol%aryl hydrogen, aromatic and aliphatic Lorentzian and Gaussian component dephasing constants, T ′ 2 s . The extreme variability in coal structure, even within a relatively homogeneous suite of coals, is evidenced in the data.