Structural parameters of Argonne coal samples: Solid-state {sup 13}C NMR spectroscopy
- Government Industrial research Institute, Kyushu, Tosu, Saga (Japan)
Solid-state {sup 13}C NMR spectroscopy was applied to the structural characterization of the Argonne standard coal samples. The apparent ratio of quaternary to tertiary aromatic carbons was determined by using combined dipolar-dephasing and cross-polarization-magic-angle spinning (CP-MAS) NMR experiments. By using the apparent ratio and the value of the fraction of aromatic carbon, several parameters can be obtained on the average chemical structure of coals. Among the Argonne samples, a low-volatile bituminous coal consists of approximately four aromatic rings with a few ethyl groups as alkyl substituents. High-volatile bituminous coals are composed of two aromatic rings with approximately two propyl groups and one hydroxyl group as substituents. Both the subbituminous and lignite coals have approximately four aromatic rings with approximately three pentyl groups and two oxygen-containing substituent groups, such as hydroxyl or carboxyl groups. 29 refs., 4 figs., 3 tabs.
- OSTI ID:
- 441408
- Report Number(s):
- CONF-891206--
- Country of Publication:
- United States
- Language:
- English
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