Combustion Inhibition Performance and Kinetic Mechanism of CF3I on the Premixed Hydrocarbon Flames

Iodotrifluoromethane (CF₃I, FIC-1311) has gained increasing attention as a Halon 1301 (CF₃Br) alternative due to its high fire-extinguishing efficiency and favorable environmental properties. However, whether CF₃I has potential hazard of combustion enhancement is still unclear. In this paper, the kinetic mechanism together with thermal chemistry of CF₃I on premixed CH₄-air and C₃H₈-air flames was systematically investigated and benchmarked against Halon 1301 (CF₃Br) and HFC-227ea (C₃F₇H) at the same conditions. The results show that CF₃I has excellent inhibition effectiveness against hydrocarbon-air flames and no combustion enhancement phenomenon is observed. In terms of fire extinguishing mechanism, CF₃I mainly relies on catalytic cycle reactions to reduce the total reaction rate by scavenging H and OH radicals. The efficiency of CF₃I on burning velocity reduction for stoichiometric CH₄-air and C₃H₈-air flames is 90% as efficient as CF₃Br and more than twice as efficient as C₃F₇H. This study provides an in-depth understanding of CF₃I on hydrocarbon flames suppression, and it is meaningful for development of new fire extinguishing technology to improve energy security.