Distribution of aliphatic and aromatic carbons in H-Coal liquids by quantitative 13C FT-n.m.r. spectroscopy

Abstract

Three H-Coal liquids, ASO, ASB, and VSO, have been characterized by quantitative FT-n.m.r. spectroscopy. FT-parameters were chosen to allow determination of aromatic:aliphatic carbon ratios to within 1% and 2% error of the theoretical and the absolute number of aromatic and aliphatic carbons in a simulated coal liquid, respectively. The aromaticity, f a , the C ar:C al ratio and, the absolute number of both the aromatic and the aliphatic carbons on a per mol basis, have been derived for each H-Coal liquid using c.m.r. in combination with other physical data. By analysis of the chemical shifts of the c.m.r. spectra, the carbon distributions in the H-Coal liquids have been estimated and compared in terms of six structural types. The molecular parameters thus derived are reasonable correlated with the average molecular structures proposed as working hypothesis for the molecular characterization of the three H-Coal liquids.