STUDY OF SOLVENT REFINED COAL BY ELEVATED-TEMPERATURE C-13 FOURIER-TRANSFORM NUCLEAR MAGNETIC-RESONANCE SPECTROMETRY

Quantitative 1H and 13C NMR techniques have been developed which allow measurement of hydrogen to carbon ratios and elemental carbon and hydrogen percentages for coal liquefaction products. Good agreement between the NMR experiment and bulk elemental combustion analysis has been obtained with chromatographic fractions of certain solvent refined coals. For Amax and Monterey SRC, the discrepancy in elemental percentages were much greater; however, these were less prominent at higher temperatures (32 vs. 75 °C). In an analogous fashion, inferred ratios of aliphatic-to-aromatic carbon decrease for the lower temperature measurements. These results suggest that certain solutions of coaly matter may experience inhomogenieties. The use of high temperature NMR solvents and high temperature examination of melts of the coal products is described as a viable alternative for 13C NMR investigation of coaly matter. © 1979, American Chemical Society. All rights reserved.