Analysis of water in Loy Yang brown coal using solid-state 1H NMR

1H spin-echo MAS NMR and 1H saturated spin-echo MAS NMR were applied to classify the water in Loy Yang coal. Adsorbed water was examined based on the proton spectra, in which four major portions were identified according to the moisture contents. Free water could be quantified by analyzing the proton free induction decays (FIDs) obtained using the 1H saturated spin-echo technique. By comparing the proton intensity of the CH portion to the aromatic and N portion in the proton spectra, and by evaluating the FIDs, the water in Loy Yang coal could be classified.