A detailed, molecule-based kinetic model has been developed to simulate industrial naphtha hydro treators. A feed characterization module has been developed to calculate the composition of pre-defined pure molecules representing the feed quality without any detailed experimental component analysis. Feed naphtha is represented by a pre-defined set of 95 pure molecules, from carbon numbers C-5 to C-11, and the proportion of these components is calculated using an optimization algorithm so as to match the physico-chemical properties of the mixture with those of naphtha, as measured in the laboratory. The output from this optimization model is used as a direct input to a model of a hydro treating reactor. The main reactions occurring in the hydro creator, such as hydro desulfurization reactions and olefin saturation reactions, are modeled. The kinetic parameters for these reactions have been estimated from a comprehensive set of experimental pilot plant data spanning a wide range of process conditions. The kinetic model quantitatively predicts the exit composition, temperature rise and pressure drop in the catalyst bed for a range of conditions for two industrial refinery units. (C) 2017 Published by Elsevier B.V.