Kinetics of flame inhibition by sodium

Abstract

When sodium is added at mole fractions of ca. 10^–4 to fuel-rich premixed hydrogen/oxygen/nitrogen flames of temperature T between 1800 and 2200 K, accelerated recombination of excess hydrogen atoms and hydroxy radicals is observed. The effect is quantitatively interpreted in terms of the reactions NaOH + H [graphic omitted] Na + H₂O, (1), Na + OH + M [graphic omitted] NaOH + M. (2) Rate coefficients are as follows: log₁₀(k₁/cm³ molecule^–1 s^–1)=– 10.75 ± 0.5 – 430 T^–1, log₁₀(k_–1/cm³ molecule^–1 s^–1)=– 9.39 ± 0.5 – 9500 T^–1, log₁₀(k₂/cm⁶ molecule^–2 s^–1)=– 26.30 ± 0.4 – log₁₀T, log₁₀(k_–2/cm³ molecule^–1 s^–1)=– 2.60 ± 0.4 – log₁₀T– 17 100 T^–1.