Spherical flame propagation Behaviors in Iron-Methane-Air mixtures

• Flame propagation of iron–methane–air mixtures was investigated experimentally. • Flame speed decreased near stoichiometric methane due to iron particle heat loss. • Under lean methane, iron oxidation supplied extra heat and enhanced propagation. • XRD showed Fe 2 O 3 formation under lean and FeO/Fe 3 O 4 under stoichiometric condition of methane-air. • Results clarify gas–solid interactions governing hybrid flame propagation. Recently, interest in metal powders such as iron has grown due to t