Weathering of oil spills accounting for oil components

A model is proposed to describe the weathering of oil spills taking into account the spreading, evaporation, emulsification, viscosity and density increase of the oil. The crude is described by a set of eight fractions, including paraffin, cycloparaffin, aromatic, naphthenoaromatic fractions and a high density residual. The evaporation process is computed for each fraction separately using a pseudo-component approach. This model is compared with another one, developed in a previous work, which treats the oil as a whole and uses evaporative exposure approach to model evaporation. The comparison of the results obtained by the two models with experimental data available in the literature shows a significant improvement when the pseudo-component approach is used, with respect to the evaporation process. (author)