Copyright © Analele UniversităĠii din Bucureúti ACTIVATION ENERGY VARIATION DURING IGNITION OF PROPANE-AIR MIXTURES ON ISOTHERMALLY HEATED PLATINUM FILAMENTS

abstract: The ignition of a stagnant stoichiometric propane-air mixture by an isothermally heated platinum filament supported on a thin quartz bar was studied at various filament temperatures between 400 and 600 K and at ambient pressure. The heterogeneous ignition over the platinum surface continues in the gaseous phase as an independent flame. The induction periods of the gas-phase ignition at various filament temperatures were used to evaluate the overall activation energy of the process.The chemical heat flux variation during surface reaction exhibits an anti Arrhenius behaviour and allows an evaluation of a continuous change of the apparent activation energy. 1