Lumped kinetic modeling of the oxidation of isocetane (2,2,4,4,6,8,8 Heptamethylnonane) in a jet-stirred reactor (JSR)

In a recent publication Dagaut and Hadj-Ali discussed the kinetics of oxidation of isocetane (2,2,4,4,6,8,8-heptamethylnonane). They carried out experiments in a jet-stirred reactor at 10 atm and a constant residence time of 1 s, over the temperature range of 770-1070 K, and for variable equivalence ratios (0.5, 1, and 2). These data were also modeled using two different computer-generated semidetailed kinetic reaction mechanisms: the POLIMI Scheme and the Nancy Scheme. Dagaut and Hadj-Ali presented comparisons between experimental and computational results, using both the mechanisms. Unfortunately, the CHEMKIN simulations they performed with the POLIMI scheme were affected by an error because of convergence problems. On the basis of these completely erroneous simulations (Figure 1a), they concluded that the model proposed by Agosta et al. poorly represents the experimental results. They also attributed this erroneous behavior to the lumping procedures and to the strong simplifications. Figure 1b shows the correct comparisons between model predictions and experimental data, when the proper convergence is attained. The agreement is quite good, the reactivity of themodel is in line with the measurements, as the profiles of the main oxidation products (CO, CO2 and H2O) testify.