A Kinetic Mechanism for CF₃I Inhibition of Methane–Air Flames

ABSTRACT

The influence of CF₃I on the burning velocity of methane–air flame is experimentally and numerically studied. Experimental results demonstrate that the inhibition effectiveness of CF₃I is very close to that of CF₃Br. A detailed kinetic model of flame inhibition by CF₃I is presented, based on an updated version of a previous model. The kinetic model contains 1072 reactions with 115 species including 10 iodine-containing species. Modeling results demonstrate good agreement with experimental data, and both experiments and calculations show that CF₃I is only slightly less effective at reducing the burning velocity than CF₃Br. The flame structure predicted from numerical simulations is analyzed and shows that main reactions of the inhibition cycle of CF₃I are as follows: H+ HI = H₂ + I; H + I + M = HI+M; I + I + M = I₂ + M; H+ I₂ = HI+I; I+ CH₃ + M = CH₃I+M; H+ CH₃I = CH₃+ HI; I+ HCO = HI+CO; HI+OH = H₂O+I and O+ HI = I+ OH.

KEYWORDS:

• Flame inhibition
• fire suppression
• halon replacements
• halogen
• CF₃I

Acknowledgments

The third author is grateful for the 2 years he had as a post-doc with Professors Libby and Williams, in which he learned the value of thoroughness and honesty in research. His days there were some of the most valuable and happiest times of his life.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Notes

¹ Official contribution of NIST, not subject to copyright in the United States. Certain commercial equipment, instruments, and materials are identified in this paper to adequately specify procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology.