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Title: The attachment of the flame sheet to the carbon surface in a carbon combustion model: On the combustion rate

Abstract

The behavior of the combustion rate of carbon, when the flame sheet attaches to or collapses at the carbon surface, is studied in a model in which the heterogeneous reactions 2C{sub (s)} + O{sub 2} {r{underscore}arrow} 2CO[reaction (I)] and C{sub (s)} + CO{sub 2} {r{underscore}arrow} 2CO[(IV)] and the homogeneous reaction 2CO + O{sub 2} {r{underscore}arrow} 2CO{sub 2}[(III)] occur in a stagnation flow of air. In this model the surface mass fraction of CO{sub 2} increases with an increase in the combustion rate. In a restricted case in which the heterogeneous reaction is solely (IV), CO{sub 2} is on the one hand the product of an overall surface reaction [reaction (III) plus (IV)] but on the other hand the reactant of reaction (IV) which determines the rate of this overall reaction. This causes peculiar variations of the combustion rate: (1) the combustion rate vanishes at a nonvanishing D{sub s(IV)}(D{sub 2(n)} is the surface Damkoehler number of the nth reaction); (2) the combustion rate varies dramatically with D{sub s(IV)} in the D{sub s(IV)} range in which the combustion rate is nonvanishing. When reaction (I) occurs at all, CO{sub 2} is made from CO by reaction (III); therefore, reaction (IV) occurs even inmore » the D{sub s(IV)} range in which this reaction never occurs by itself. When D{sub s(IV)} is kept constant and D{sub s(I)} is increased, the combustion rate and the contribution of the gasification of carbon by reaction (I) naturally increase, but, because of an increase in the surface mass fraction of CO{sub 2} with increasing combustion rate, the contribution by reaction (IV) also increases.« less

Authors:
Publication Date:
Research Org.:
Daicel Chemical Industries, Ltd., Hyogo (JP)
OSTI Identifier:
20000567
Resource Type:
Journal Article
Journal Name:
Combustion and Flame
Additional Journal Information:
Journal Volume: 118; Journal Issue: 4; Other Information: PBD: Sep 1999; Journal ID: ISSN 0010-2180
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; CARBONACEOUS MATERIALS; COMBUSTION KINETICS; MATHEMATICAL MODELS; CARBON DIOXIDE; CARBON MONOXIDE; CARBON

Citation Formats

Matsui, Kiyoshi. The attachment of the flame sheet to the carbon surface in a carbon combustion model: On the combustion rate. United States: N. p., 1999. Web. doi:10.1016/S0010-2180(99)00024-3.
Matsui, Kiyoshi. The attachment of the flame sheet to the carbon surface in a carbon combustion model: On the combustion rate. United States. doi:10.1016/S0010-2180(99)00024-3.
Matsui, Kiyoshi. Wed . "The attachment of the flame sheet to the carbon surface in a carbon combustion model: On the combustion rate". United States. doi:10.1016/S0010-2180(99)00024-3.
@article{osti_20000567,
title = {The attachment of the flame sheet to the carbon surface in a carbon combustion model: On the combustion rate},
author = {Matsui, Kiyoshi},
abstractNote = {The behavior of the combustion rate of carbon, when the flame sheet attaches to or collapses at the carbon surface, is studied in a model in which the heterogeneous reactions 2C{sub (s)} + O{sub 2} {r{underscore}arrow} 2CO[reaction (I)] and C{sub (s)} + CO{sub 2} {r{underscore}arrow} 2CO[(IV)] and the homogeneous reaction 2CO + O{sub 2} {r{underscore}arrow} 2CO{sub 2}[(III)] occur in a stagnation flow of air. In this model the surface mass fraction of CO{sub 2} increases with an increase in the combustion rate. In a restricted case in which the heterogeneous reaction is solely (IV), CO{sub 2} is on the one hand the product of an overall surface reaction [reaction (III) plus (IV)] but on the other hand the reactant of reaction (IV) which determines the rate of this overall reaction. This causes peculiar variations of the combustion rate: (1) the combustion rate vanishes at a nonvanishing D{sub s(IV)}(D{sub 2(n)} is the surface Damkoehler number of the nth reaction); (2) the combustion rate varies dramatically with D{sub s(IV)} in the D{sub s(IV)} range in which the combustion rate is nonvanishing. When reaction (I) occurs at all, CO{sub 2} is made from CO by reaction (III); therefore, reaction (IV) occurs even in the D{sub s(IV)} range in which this reaction never occurs by itself. When D{sub s(IV)} is kept constant and D{sub s(I)} is increased, the combustion rate and the contribution of the gasification of carbon by reaction (I) naturally increase, but, because of an increase in the surface mass fraction of CO{sub 2} with increasing combustion rate, the contribution by reaction (IV) also increases.},
doi = {10.1016/S0010-2180(99)00024-3},
journal = {Combustion and Flame},
issn = {0010-2180},
number = 4,
volume = 118,
place = {United States},
year = {1999},
month = {9}
}