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Title: A detailed kinetic modeling study of aromatics formation in laminar premixed acetylene and ethylene flames

Abstract

A computational study was performed for the formation and growth of polycyclic aromatic hydrocarbons (PAHs) in laminar premixed acetylene and ethylene flames. A new detailed reaction mechanism describing fuel pyrolysis and oxidation, benzene formation, and PAH mass growth and oxidation is presented and critically tested. It is shown that the reaction model predicts reasonably well the concentration profiles of major and intermediate species and aromatic molecules in a number of acetylene and ethylene flames reported in the literature. It is demonstrated that reactions of n-C{sub 4}H{sub x} + C{sub 2}H{sub 2} leading to the formation of one-ring aromatics are as important as the propargyl recombination, and hence must be included in kinetic modeling of PAH formation in hydrocarbon flames. It is further demonstrated that the mass growth of PAHs can be accounted for by the previously proposed H-abstraction-C{sub 2}H{sub 2}-addiction mechanism.

Authors:
 [1];  [2]
  1. Univ. of Delaware, Newark, DE (United States). Dept. of Mechanical Engineering
  2. Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering
Publication Date:
OSTI Identifier:
543434
Resource Type:
Journal Article
Resource Relation:
Journal Name: Combustion and Flame; Journal Volume: 110; Journal Issue: 1-2; Other Information: PBD: Jul 1997
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 02 PETROLEUM; ACETYLENE; ETHYLENE; COMBUSTION KINETICS; POLYCYCLIC AROMATIC HYDROCARBONS; MATHEMATICAL MODELS; CHEMICAL REACTION YIELD; PYROLYSIS; OXIDATION; REACTION INTERMEDIATES

Citation Formats

Wang, H., and Frenklach, M.. A detailed kinetic modeling study of aromatics formation in laminar premixed acetylene and ethylene flames. United States: N. p., 1997. Web. doi:10.1016/S0010-2180(97)00068-0.
Wang, H., & Frenklach, M.. A detailed kinetic modeling study of aromatics formation in laminar premixed acetylene and ethylene flames. United States. doi:10.1016/S0010-2180(97)00068-0.
Wang, H., and Frenklach, M.. Tue . "A detailed kinetic modeling study of aromatics formation in laminar premixed acetylene and ethylene flames". United States. doi:10.1016/S0010-2180(97)00068-0.
@article{osti_543434,
title = {A detailed kinetic modeling study of aromatics formation in laminar premixed acetylene and ethylene flames},
author = {Wang, H. and Frenklach, M.},
abstractNote = {A computational study was performed for the formation and growth of polycyclic aromatic hydrocarbons (PAHs) in laminar premixed acetylene and ethylene flames. A new detailed reaction mechanism describing fuel pyrolysis and oxidation, benzene formation, and PAH mass growth and oxidation is presented and critically tested. It is shown that the reaction model predicts reasonably well the concentration profiles of major and intermediate species and aromatic molecules in a number of acetylene and ethylene flames reported in the literature. It is demonstrated that reactions of n-C{sub 4}H{sub x} + C{sub 2}H{sub 2} leading to the formation of one-ring aromatics are as important as the propargyl recombination, and hence must be included in kinetic modeling of PAH formation in hydrocarbon flames. It is further demonstrated that the mass growth of PAHs can be accounted for by the previously proposed H-abstraction-C{sub 2}H{sub 2}-addiction mechanism.},
doi = {10.1016/S0010-2180(97)00068-0},
journal = {Combustion and Flame},
number = 1-2,
volume = 110,
place = {United States},
year = {Tue Jul 01 00:00:00 EDT 1997},
month = {Tue Jul 01 00:00:00 EDT 1997}
}
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  • Abstract not provided.
  • In this paper, the prediction of a soot model [J. Appel, H. Bockhorn, M. Frenklach, Combust. Flame 121 (2000) 122-136] is compared to a recently published set of highly detailed soot particle size distributions [B. Zhao, Z. Yang, Z. Li, M.V. Johnston, H. Wang, Proc. Combust. Inst. 30 (2005)]. A stochastic approach is used to obtain soot particle size distributions (PSDs). The key features of the measured and simulated particle size distributions are identified and used as a simple way of comparing PSDs. The sensitivity of the soot PSDs to the parameters defining parts of the soot model, such asmore » soot inception, particle and PAH collision efficiency and enhancement, and surface activity is investigated. Incepting soot particle size is found to have a very significant effect on the small-size end of the PSDs, especially the position of the trough for a bimodal soot PSDs. A new model for the decay in the surface activity is proposed in which the activity of the soot particle depends only on the history of that particle and the local temperature in the flame. This is a first attempt to use local flame variables to define the surface aging which has major impact on the prediction of the large-size end of the PSDs. Using these modifications to the soot model it is possible to improve the agreement between some of the points of interest in the simulated and measured PSDs. The paper achieves the task to help advance the soot models to predict soot PSD in addition to soot volume fraction and number density, which has been the focus of the literature. (author)« less