Yields of Polycyclic Aromatic Hydrocarbons from the Pyrolysis of Catechol [ortho-Dihydroxybenzene]: Temperature and Residence Time Effects
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- 作者：Nathan D. Marsh ; Elmer B. Ledesma ; Alyssa K. Sandrowitz ; and Mary J. Wornat
- 刊名：Energy & Fuels
- 出版年：2004
- 出版时间：January 2004
- 年：2004
- 卷：18
- 期：1
- 页码：209 - 217
- 全文大小：239K
- 年卷期：v.18,no.1(January 2004)
- ISSN：1520-5029
文摘
To understand in more detail the formation of polycyclic aromatic hydrocarbons (PAH) fromcomplex fuels, we have performed pyrolysis experiments in a laminar-flow reactor, using themodel fuel catechol (ortho-dihydroxybenzene), a phenol-type compound representative of structuralentities in tobacco, coal, and wood. Catechol pyrolysis at temperatures of 700 to 1000 
C andresidence times of 0.4 to 1 s produces a range of aromatic products, which have been analyzed bygas chromatography with flame-ionization detection and by high-pressure liquid chromatographywith diode-array ultraviolet-visible absorption detection. Of the 64 aromatic products identified,yields are reported for the 30 species whose yields are at least 0.005% of the mass of fed catechol,over a significant temperature range. The quantified products fall into 8 structural categories:benzene, benzenoid PAH, indene benzologues, fluoranthene benzologues, cyclopenta-fused PAH,ethynyl-substituted aromatics, alkyl-substituted aromatics, and vinyl-substituted aromatics. Ingeneral, the more prominent products within a particular structural class are more prominentat all temperatures examined, and the most prominent product in a class is usually 10 timesmore prevalent than other compounds in the same class. The product quantifications show thatat 900-950 C, the aromatic products account for up to 22% of the mass of fed catechol. At thesehigher temperatures, and all the way up to 1000 C, there are also more quantifiable productsthat are the result of multiple ring-buildup steps (e.g., the larger benzenoid PAH) as well as anincrease in the number and relative quantity of ethynyl-aromatics and cyclopenta-fused PAH.At the lower temperatures, indene is produced at especially high yield, indicative perhaps of aparticular facility for the formation of indene from catechol. Also readily formed from catechol isbenzene, the aromatic product of highest yield for the entire temperature range investigated.Experiments at different residence times show that at 800 C the 0.4-1 s time interval is one ofmostly increasing yields; at 1000 C this same span of residence times sees mostly decreasingyields. The data reported here represent one of the most extensive quantifications of aromaticproducts from any fuel, and the only one for catechol.
C andresidence times of 0.4 to 1 s produces a range of aromatic products, which have been analyzed bygas chromatography with flame-ionization detection and by high-pressure liquid chromatographywith diode-array ultraviolet-visible absorption detection. Of the 64 aromatic products identified,yields are reported for the 30 species whose yields are at least 0.005% of the mass of fed catechol,over a significant temperature range. The quantified products fall into 8 structural categories:benzene, benzenoid PAH, indene benzologues, fluoranthene benzologues, cyclopenta-fused PAH,ethynyl-substituted aromatics, alkyl-substituted aromatics, and vinyl-substituted aromatics. Ingeneral, the more prominent products within a particular structural class are more prominentat all temperatures examined, and the most prominent product in a class is usually 10 timesmore prevalent than other compounds in the same class. The product quantifications show thatat 900-950 C, the aromatic products account for up to 22% of the mass of fed catechol. At thesehigher temperatures, and all the way up to 1000 C, there are also more quantifiable productsthat are the result of multiple ring-buildup steps (e.g., the larger benzenoid PAH) as well as anincrease in the number and relative quantity of ethynyl-aromatics and cyclopenta-fused PAH.At the lower temperatures, indene is produced at especially high yield, indicative perhaps of aparticular facility for the formation of indene from catechol. Also readily formed from catechol isbenzene, the aromatic product of highest yield for the entire temperature range investigated.Experiments at different residence times show that at 800 C the 0.4-1 s time interval is one ofmostly increasing yields; at 1000 C this same span of residence times sees mostly decreasingyields. The data reported here represent one of the most extensive quantifications of aromaticproducts from any fuel, and the only one for catechol.