Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Catalytic Inhibition of Laminar Flames by Transition Metal Compounds

Published

Author(s)

Gregory T. Linteris, M D. Rumminger, Valeri I. Babushok

Abstract

Some of the most effective flame inhibitors ever found are metallic compounds. Their effectiveness, however, drops off rapidly with an increase of agent concentration, and varies widely with flame type. Iron pentacarbonyl, for example, can be up to two orders of magnitude more efficient than CF3Br for reducing the burning velocity of premixed laminar flames when added at low volume fraction; nevertheless, it is nearly ineffective for extinction of co-flow diffusion flames. This article outlines previous research into flame inhibition by metal-containing compounds, and focuses on the authors recent experimental and modeling studies of inhibited premixed, counterflow diffusion, and co-flow diffusion flames. The strong flame inhibition by metal compounds when added at low volume fraction is found to occur through the gas-phase catalytic cycles leading to a highly effective radical recombination in the reaction zone. While the reactions of these cycles proceed in some cases at close to collisional rates, the agent effectiveness requires that the inhibiting species and the radicals in the flame overlap, and this can sometimes be limited by gas-phase transport rates. The metal species often lose their effectiveness above a certain volume fraction due to condensation processes. The influence of particle formation on inhibitor effectiveness depends upon the metal species concentration, particle size, residence time for particle formation, local flame temperature, and the drag and thermophoretic forces in the flame.
Citation
Progress in Energy and Combustion Science
Volume
34
Issue
3

Keywords

flame inhibition, halon replacement, fire suppression, nanoparticles, fuel additives

Citation

Linteris, G. , Rumminger, M. and Babushok, V. (2008), Catalytic Inhibition of Laminar Flames by Transition Metal Compounds, Progress in Energy and Combustion Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=900170 (Accessed March 29, 2024)
Created June 1, 2008, Updated February 19, 2017