DISTRIBUTION AND CHARACTERIZATION OF PHENOLICS IN DISTILLATES DERIVED FROM 2-STAGE COAL-LIQUEFACTION

The nature and distribution of the phenolic fractions isolated from 175-425 °C coal-derived distillates have been quantified. These products were from liquefaction runs made at the Advanced Coal Liquefaction R & D Facility at Wilsonville, AL. The concentrations of moderate to low boiling phenolics were determined by isolating an acidic concentrate by extraction with sodium hydroxide, freeing the phenolics by acid addition, and analyzing the fraction by gas chromatography/mass spectrometry and high-resolution mass spectrometry. The phenolics derived from both Illinois No. 6 and Wyodak coals are primarily found in the 175-315 °C boiling range. They chiefly consist of four types of ring structures: phenols, indanols, naphthols, and biphenylols/acenaphthols. Most of these compounds are alkyl substituted with short chains. Longer chains appear to be branched. During liquefaction, the recycling of mineral matter plus uncoverted coal along with the solvent shows catalytic activity for deoxygenation; however, this activity is not selective toward individual phenolic species. With the introduction of a catalyst to the first-stage reactor, additional deoxygenation occurs, and there is a trend toward selectively reducing nonhindered phenolics. © 1990, American Chemical Society. All rights reserved.