Modelling of Acetaldehyde or Propane Oxidation

Detailed Modelling of Acetaldehyde or Propane Oxidation.— The second approach, stated at the outset, attempts to choose a complete kinetic mechanism of a specific system and to proceed to a numerical solution of the detailed mass and energy balance equations via a digital computer. This is the approach chosen by Halstead et al. who have concentrated on the gas-phase oxidations first of acetaldehyde and latterly of propane. In the acetaldehyde reaction, Halstead et al. identified peracetic acid as the degenerate branching agent and attributed the self-quenching 

Even at this stage only a small minority of the CHjCX) radicals react this way, the majority reacting via 

During self-heating of the cool flame, the temperature rise results in (Rl) competing less favourably with (R3), the high activation energy reaction. Die falling value of the ratio of rates of (Rl) to (R3), together with the promotion with increase in temperature of the reaction 

In general the predictions of detailed modelling, in terms of both the location of the p-F. ignition diagram and the shape and duration of cool-flame temperature-time histories, is in encouraging agreement with experimental measurements. Two points are worthy of note  

At present it would seem as if detailed modelling is most profitable after vindication of a generalized approadi and is not a realistic indepraident altmiativc. Progress 1 both paths has deepened understanding in the study of hydrocarbon oxidation. From being the most mysterious, periodic cool flames have become the best undostood of oscillatory chemical reactions. 

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