Wa. Hartgers et al., MOLECULAR CHARACTERIZATION OF FLASH PYROLYSATES OF 2 CARBONIFEROUS COALS AND THEIR CONSTITUTING MACERAL FRACTIONS, Energy & fuels, 8(5), 1994, pp. 1055-1067
Two high-volatile bituminous Upper Carboniferous coals from the Argonn
e Premium Coal Set and their constituting liptinite, vitrinite, and in
ertinite fractions, obtained by density gradient centrifugation (DGC),
were characterized by Curie point pyrolysis-gas chromatography-mass s
pectrometry. A detailed analysis of the pyrolysis products was perform
ed to relate individual macerals to their (plant-derived) precursors.
Liptinite fractions were found to be mainly composed of sporinite, the
diagenetic product of sporopollenin. Its aliphatic character was refl
ected in its pyrolysate by the abundance and characteristic distributi
on of n-alk-1-enes and n-alkanes showing maxima at C-11 and C-25 Moreo
ver, a selective enrichment of aromatic components derived from linear
carbon skeletons via cyclization and aromatization of functionalized,
linear precursors was observed. In the sulfur-rich Illinois No. 6 coa
l, the addition of abiotic inorganic sulfur species to functional grou
ps was reflected by a selective enrichment of organic sulfur compounds
in the liptinite maceral. Diagenetically altered lignin derived from
gymnospermous wood is the most likely precursor for vitrinite, the maj
or constituent of both coals. Flash pyrolysates of vitrinite fractions
were dominated by alkylbenzenes and alkylphenols. Inertinite fraction
s exhibited relatively high amounts of(poly)aromatic pyrolysis product
s. Thermal extraction experiments revealed that these components were
mainly present as such adsorbed to or entrapped in the pore system of
the maceral matrix.