Iranian Journal of Chemical Engineering (IJChE)

Abstract Monte Carlo simulation is adopted to study the aggregation of asphaltene phenomenon in crude oil. Simulation is accomplished by applying two different potential functions to allow for asphaltene-asphaltene, asphaltene- resin and resin-resin interactions to take place. Asphaltene molecule is considered as a flat molecule, consisting of seven spheres. Resin molecule is considered to be a single sphere and the other hydrocarbons molecules contained in crude oil are modeled as a continuum media. The effect of media on intermolecular interactions is described by definition of a parameter that is composed of two dielectric and Hamaker constants. The effects of asphaltene concentration, temperature and solvent type on the aggregation of asphaltene molecules are investigated by applying both of the potential functions. The predicted results are compared.

Abstract The influence of different factors on the asphaltene stability in three iranian crude oils was evaluated. Compositional studies and structural characterization of resins and asphaltenes were carried out in order to study a possible relationship between these properties and asphaltene deposition behavior. Low hydrogen to carbon ratios and high aromaticities were the main characteristics of the asphaltenes from more unstable crude oils. According to these results, the stability behavior of asphaltenes was influenced strongly by their structural characteristics. Colloidal stability indexes such as the (aromatic+resins)/(asphaltene+saturates) ratio and (aromatics+resins)/ asphaltene ratio do not play a key role in the asphaltene stability for the studied crude oils.