Shock-tube and modeling study of acetone pyrolysis and oxidation

Pyrolysis and oxidation of acetone were studied behind reflected shock waves in the temperature range 1050-1650 K at total pressures between 1.2 and 3.2 atm. The study was carried out using the following methods, (1) time-resolved IR-laser absorption at 3.39 mu m for acetone decay and CH-compound formation rates, (2) time-resolved UV absorption at 200 nm for acetone decay and product formation rates, (3) time-resolved UV absorption at 306.7 nm for the OH radical formation rate, (4) time-resolved IR emission at 4.24 mu m for the CO2 formation rate, and (5) a single-pulse technique for product yields. From a computer simulation, a 164-reaction mechanism that could satisfactorily model all of our data was constructed that includes the most recent submechanisms for methane, acetylene, ethylene, ethane, formaldehyde, and ketene oxidation. The rate constants of reactions 1 and 2 were evaluated as k(1) = 1.13 x 10(16) exp(-81.7 kcal/RT) s(-1) and k(2) = 2.30 x 10(7)T(2.0) exp(-5.00 kcal/RT) cm(3) mol(-1) s(-1) (CH3)(2)CO --> CH3CO + CH3, (CH3)(2)CO + H --> CH3COCH2 + H-2. The submechanisms of methane, ethylene, ethane, formaldehyde, and ketene were found to play an important role in acetone oxidation. (C) 2000 by The Combustion Institute.