PCS-469

Application of a spectral deconvolution technoque to coal FT-IR spectra
Kroo, E.; Bonanno, A.S.; Serio, M.A.; Solomon, P.R.
Proceedings, 7th International Conference on Coal Science 1993 II 473-476


This work demonstrates application of a simple curve-resolving technique to the 3000-3340 and 1474-1800 cm[sup -1] regions of FT-IR spectra for a wide range of coal ranks and modified coals to obtain new information on coal structure not available by other techniques. Parameters were set up by combining conventional second derivation with available literature data and then were applied to the whole set of coal samples to measure relative concentrations of carboxyl, carbonyl and different H- bonded OH functionalities. The free carboxyl groups were determined by differentiating H-bonded and free carbonyls from carboxy carbonyls and carboxylates. A decrease of OH, CO and carboxyl concentrations with coal rank was shown. A correlation between the strength of the aromatic [pi] electron-H bonding and the aromatic ring breathing band position (around 1610 cm[sup -1]) was also shown. Our measurements confirm an earlier suggestion based on NMR data that the H[sub 2]O in the coal matrix can be found in tightly and loosely bound forms. FT-IR data for Zap (Argonne) coal show the non-interacting water to be at about 10% moisture content. 22 refs., 4 figs., 1 tab.

8. Beulah-Zap, ND (ND)