The importance of peroxy radical chain-breaking reactions in the cool flame domain
This article describes experiments to quantify the link between temperature increase and radical concentration and the part played by alkyl peroxy radicals RO 2 in the kinetics of the low-temperature oxidation of n-heptane. The flow method is used, at atmospheric pressure, with two reactors, one of...
Saved in:
Published in | Combustion and flame Vol. 34; pp. 153 - 159 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Inc
1979
|
Online Access | Get full text |
Cover
Loading…
Summary: | This article describes experiments to quantify the link between temperature increase and radical concentration and the part played by alkyl peroxy radicals RO
2 in the kinetics of the low-temperature oxidation of
n-heptane. The flow method is used, at atmospheric pressure, with two reactors, one of boric acid-coated Pyrex glass, and the other of stainless steel. The stabilized slow reaction and cool flame are studied by means of electron spin resonance (esr) and thermal measurements. When a slow reaction occurs the radical concentration and temperature profiles versus distance have coincident maxima. For a slow reaction followed by a cool flame the profiles show a relative shift. The concentration maximum always precedes the temperature one and occurs when the temperature rise reaches approximately the critical value
ΔT
crit. In the flame (between
ΔT
crit and the temperature maximum) the RO
2 concentration decreases drastically. As a new explanation for the cool flame self-inhibition and hence periodicity, we propose a sequence of chain-breaking (or slowing down) reactions, between RO
2 and active centers produced by peroxide decomposition in the cool flame. |
---|---|
ISSN: | 0010-2180 1556-2921 |
DOI: | 10.1016/0010-2180(79)90088-9 |