Tetralin, indane, and fluorene molecules in a hydrogenated diesel were selectively oxidized with air to determine their kinetic behavior during the reaction. The oxidation of model molecules was performed in a continuous stirred tank reactor to obtain data to simulate diesel oxidation in a slurry (three-phase) reactor. The products of reactions were analyzed by elution in a silica column followed by CC-MS analysis of the fractions to determine the amount of product converted. The analytical procedure was calibrated using the model molecules. A lump model of 11 main reactions is considered here to evaluate the conversion of tetralin, indane, and fluorene into oxygenated compounds. The kinetic study was performed at different temperatures, space velocities, and reactant concentrations. A program using a genetic algorithm optimization tool was developed to calculate the values of the kinetics rate constants. The results indicated that the reaction can be modeled by a simple apparent first order of reaction with respect to hydrocarbon and around 0.3 orders of reaction respects to oxygen. The reactivity followed the order tetralin, indane, and then fluorene. The heterogeneous kinetic rate expressions of one active site represent the experimental results in the range of operating conditions studied. Under the experimental conditions, the ketones and ketols formed are strongly adsorbed in the active sites. Production of alcohols generates some poly-oxygenated compounds that reduce the storage stability of the fuel. (C) 2008 Elsevier Ltd. All rights reserved.