LOW AND INTERMEDIATE TEMPERATURE ETHANE COMBUSTION MODELING

In models developed for hydrocarbon combustion processes in the low and intermediate temperature regime, the shift from peroxide to olefin production has been usually simulated through the competition between the reactions: R + O-2 [-] RO(2) R + O-2 --> olefin + HO2 Recent studies on ethyl radical oxidation routes suggest that the main reaction leading to C2H4 could be C2H5OO --> C2H4 + HO2 A model of ethane oxidation process in the temperature range 593 K-626 K has been developed, on the basis f the above results. Model simulations have been compared with Nalbandyan school experiments in a static vessel for a C2H6/O-2 = 2 molar ratio, at a total pressure of 81.2 kPa, for 593 K-626 K temperature range, in conditions for which the ethane oxidation process exhibits a negative temperature coefficient. A peculiar property of ethane combustion process appears to be that the negative temperature coefficient can be revealed only from dependence of overall reaction rate, since induction time still retains a normal positive temperature coefficient. The detailed kinetic scheme includes 47 chemical species involved in 202 reactions. Analyses of results indicate that indeed the novel reaction channel is important for ethane combustion description. Analyses of OH formation and consumption rates permit to explain the negative temperature coefficient, which is simulated according to the peculiar ethane property.