Polycyclic aromatic hydrocarbons from the pyrolysis of catechol (ortho-dihydroxybenzene), a model fuel representative of entities in tobacco, coal, and lignin
Mj. Wornat et al., Polycyclic aromatic hydrocarbons from the pyrolysis of catechol (ortho-dihydroxybenzene), a model fuel representative of entities in tobacco, coal, and lignin, FUEL, 80(12), 2001, pp. 1711-1726
In order to better understand the formation of polycyclic aromatic hydrocar
bons (PAH) from complex fuels, we have performed pyrolysis experiments in a
laminar-flow reactor, using the model fuel catechol (ortho-dihydroxybenzen
e), a phenol-type compound representative of structural entities in tobacco
, coal, and wood. Employing high pressure liquid chromatography with diode-
array ultraviolet-visible (UV) detection, we have unequivocally identified
59 individual species among the condensed-phase products of catechol pyroly
sis at a temperature of 1000 degreesC and a residence time of 0.4 s. Also i
dentified are two oxygen-containing compounds that are produced only at pyr
olysis temperatures lower than 900 degreesC. Of the total 61 species, fifty
have never before been identified as pyrolysis products of any pure phenol
-type compound. Two of the catechol pyrolysis products, 5-ethynylacenaphthy
lene and 3-ethynylphenanthrene, have never before been identified as produc
ts of any fuel. Ranging in size from one to eight fused aromatic rings, the
catechol pyrolysis products comprise several compound classes: bi-aryls, i
ndene benzologues, benzenoid PAH, alkylated aromatics, fluoranthene benzolo
gues, cyclopenta-fused PAH, ethynyl-substituted aromatics, polyacetylenes,
and oxygen-containing aromatics. The catechol pyrolysis products bear remar
kable compositional similarity to the products of bituminous coal volatiles
pyrolyzed at the same temperature - demonstrating the relevance of these c
atechol model compound experiments to the study of complex fuels such as co
al, wood, and tobacco. The UV spectra, establishing compound identity, are
presented for several of the identified catechol product components. (C) 20
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