Quantitative characterization of coal properties using bidirectional diffuse reflectance spectroscopy

The 0.3-26 mum (33,000-385 cm(-1)) reflectance spectra of the <45 mum fractions of a series of coal samples ranging from lignite to anthracite were analyzed in conjunction with compositional information to derive spectral-compositional-structural relationships. The reflectance spectra, particularly in the 1.8-4 mum (5500-2500 cm(-1)) region exhibit a number of absorption features attributable to both the organic and inorganic components. Quantitative spectral-compositional relationships were found which permit the derivation of properties such as aromaticity, total aliphatic, aromatic content, moisture content, volatile content, fixed carbon abundance, fuel ratio, carbon content, nitrogen abundance, H/C ratio, and vitrinite reflectance. In general, all absorption bands become less intense, and overall reflectance decreases with increasing rank. (C) 2003 Elsevier Ltd. All rights reserved.