Linkages and aromatic clusters in a bituminous coal. Quarterly technical progress report No. 2, December 1, 1985-February 28, 1986

The objectives of this investigation are: (1) quantitative characterization of a bituminous coal in terms of its major compositon and molecular structural characteristics needed to assess its liquefaction reactivity, and (2) extending this characterization methodology for a specific examination of aliphatic linkages of the coal. The characterization methodology consists of a controlled depolymerization of the sample coal, solvent extraction of the products, and detailed analysis of the product fractions. For the specific examination of aliphatic linkages, well-characterized soluble fractions from the same coal will be investigated by a transalkylation reaction. An Illinois No. 6 coal was solubilized in reactions with NaOH/ethanol/ H/sub 2/O at 260/sup 0/ and 300/sup 0/C, which are called Ill-260 and Ill-300, respectively. The product from Ill-260 was fractionated, and the fractions are being analyzed. The product from Ill-300 is being fractionated. In Ill-260, 86% of the feed was converted to soluble products with an additional 1.6% converted to CO/sub 2/. Carbon recovery was 97.3%, and hydrogen and oxygen recoveries were 108% and 123%, respectively. Most of ash, 94%, was removed in the reaction. The atomic H/C ratio of the condensed-phase product increased to 0.89 from 0.80 of the feed coal. The atomic ratio of incorporated hydrogenmore » to oxygen was 2, indicating the hydrolysis of oxygen functional groups in the solubilization reaction. The product distribution in Ill-260 was substantially different from those with two low-rank coals in our earlier studies. The in spectra of the product fractions showed weaker absorptions due to -OH and -COOH than similar fractions from the low-rank coals. The differences are attributed to dissimilar contents of oxygen functional groups in the coals. The solubilization reaction was effective for ''depolmerization'' of the bituminous coal.« less