Kinetic studies in stirred reactors: Combustion of carbon monoxide and propane

The burning rates of carbon monoxide and of propane premixed with oxygen, nitrogen, and water vapor in various proportions were measured over ranges of equivalence ratios and pressures. Burning rates were determined from metered flow rates and analysis of reactor products. The burning rate of carbon monoxide g moles/ml (sec) can be expressed as N ˙ C O 2 = 12 × 10 10 exp ⁡ ( − 16 , 000 / R T ) f O 2 0.3 f C O f H 2 O 0.5 ( P / R T ) 1.8 (T in oK, P in atm, f = mole fraction in reactor); that of propane as N ˙ C O 2 = 2.9 × 10 10 exp ⁡ ( − 15 , 000 / R T ) f O 2 0.35 f C O f H 2 O 0.4 ( P / R T ) 1.75 A kinetic mechanism is proposed which fits the data for CO with rate constants consistent with literature values. It calls for the rate-limiting step CO+OH→CO2+H, (1) equilibrium for the following reactions: OH+H2=H2O+H (2) H+O2=OH+O (3) O+H2=OH+H (4) and a three-body chain terminating step. The mechanism proposed for propane combustion involves in addition the very fast reaction of propane to CO and H2O at the expense of OH, O, and H.