By conducting an excimer laser photolysis (193 and 248 nm) behind shock waves, three elementary reactions important in the oxidation of H2S have been examined, where, H, O, and S atoms have been monitored by the atomic resonance absorption spec-trometry, For HS + O2 → products (1), the rate constants evaluated by numerical simulations are summarized as: k1 = 3,1 × 10-11exp[- 75 kJ mol-1/RT] cm3molecule-1 (T = 1400-1850 K) with an uncertainty factor of about 2. Direct measurements of the rate con-stants for S + O2 → SO + O (2), and SO + O2 → SO2 + O (3) yield k2 = (2.5 ± 0,6) × 10-11 exp[-(15.3 ± 2.5) kJ mol-1/RT] cm3 molecule-1s-1 (T = 980-1610 K) and, k3 = (1.7 ± 0.9) × 10-12exp[-(34 ± 11) kJ mol-1 cm3molecule-1s-1s-1 (T = 1130-1640 K), respectively. By summarizing these data together with the recent experimental results on the H-S-O reaction systems, a new kinetic model for the H2S oxidation process is constructed, It is found that this simple reaction scheme is consistent with the experimental result on the in-duction time of SO2 formation obtained by Bradley and Dobson.
|Number of pages||10|
|Journal||International Journal of Chemical Kinetics|
|State||Published - 1 Jan 1997|