3. Characterization of Aromatic Ring Systems in a Victorian Brown Coal by means of UV/VIS absorption and fluorescence spectroscopy

Abstract

An attempt was made for obtaining UV/VIS absorption and fluorescence spectra of a whole Victorian brown coal and then examining the presence and abundance of poly-condensed aromatic ring systems (ARSs) in the coal. More than 99% of Loy Yang brown coal dissolved into aqueous NaOH solution at 473K. The absorption spectrum of the solubilized coal gives a direct indication of presence of ARSs with three to six condensed rings. Difference between the spectra of the solubilized coal and those of a tar sample from pyrolysis of the coal suggests that smaller ARSs are released as tar from the coal to preferentially to larger ARSs during the pyrolysis.