Sequential low-temperature depolymerization and liquefaction of US coals. Progress report No. 8, July 1--September 30, 1988

The quantitative {sup 13}C NMR, PMR, GC/MS, and FTIR data, as well as elemental composition data for the depolymerized products obtained from Beulah Zap and Pittsburgh no. 8 coals, (Progress Reports no. 5 and 7; and present report) were input into a structural analysis computer program, based on a modified Brown-Ladner method, to derive average structural parameters and, thereby, average molecular structures for the above-mentioned depolymerized coal products. The emphasis was on the structural analysis of the predominant, 65--80 wt%, oil fractions (cyclohexane-solubles) of the depolymerized products. Examples of average molecular structures derived for the oil fractions of depolymerized Pittsburgh no. 8 coal and Beulah Zap lignite are given in Figure 9. These monocluster structures indicate some features which are typical for some of the components comprising the above oil fractions. However, based on (a) the molecular weight distribution of the fractions as determined by mass spectral analysis; and (b) FTIR data indicating the type and relative concentration of oxygen-containing functional groups in the fractions, ft is possible to design molecular structures for probable components in the above two oil fractions, including mostly monocluster (mono-, bi-, and tricyclic) compounds, accompanied by small amounts of bicluster components. Some examples of probable components in the oil fractions of depolymerized Pittsburgh no. 8 coal and Beulah Zap lignite are indicated in Figure 10