Byrd Stadium lignite

Figure 3 is a collection of C CP/MAS spectra of coals of various rank.9 These spectra are representative of the appearances of most of the CP/MAS spectra of coals that we have seen. They consist primarily of bands in two regions. These are the range from about 170 to about 90 ppm and from about 80 to about 0 ppm. The first band consists mainly of aromatic carbon resonances, and the latter is due mainly to aliphatic carbons. The "aromatic" and "aliphatic" bands are relatively featureless, but some reproducible shoulders can be discerned on some of the peaks, especially for the lower-rank coals. Indeed, some of the lignites show a considerable degree of fine structure, as exemplified by the spectrum of Byrd Stadium lignite shown in Figure 4. This additional fine structure can be attributed to specific structural features (e.g., a shoulder at about 155 ppm attributed to oxygen-substituted carbon in a phenolic system).

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