EXPERIMENTAL KINETICS AND MECHANISTIC MODELING OF THE OXIDATION OF SIMPLE MIXTURES IN NEAR-CRITICAL WATER

A novel kinetics lumping strategy is assessed through the confrontation of experimental kinetics for the hydrothermal oxidation of mixtures of simple alcohols and acetic acid with the predictions of a mechanistic model. According to this lumping strategy, each of the elementary steps in the reaction model was lumped into one of eight reaction families. Each reaction family, in turn, was assigned an Arrhenius A factor, a Polanyi relation slope alpha = 0.5, and a Polanyi parameter E(o)* determined via optimization to previous pure component experimental data only. Quantitative prediction of the kinetics of mixtures of these components was achieved by adjusting only the A factor for the H-abstraction reaction family to the value log10 A (L/mol.s)) = 8.3, characteristic of H-abstraction for secondary alcohols. In short, the 167 rate constants of the mechanistic model were predicted by the eight reaction family parameter vectors [A:alpha:E(o)*] such that an excellent correlation (r2 = 0.987) existed between experimental (gamma(E)) and predicted (gamma(P)) yields.