Effects of Styrene Ionomers on the Dispersion of Asphaltenes in Crude Heavy Oil

The purpose of this work was to investigate the effects of polystyrene-based acidic copolymers and ionomers on the dispersion of asphaltenes in heavy oil. In the first part of the work, we studied the effect of the addition of sulfonated polystyrene acidic copolymers (SSA) and Na-neutralized ionomers (SSNa) on asphaltene dispersion. It was found that the SSA copolymers and the low ion content SSNa ionomers did not show asphaltene dispersion enhancement. However, high ion content SSNa ionomers improved asphaltene dispersion. In the second part of the work, styrene–methacrylate ionomers (SMANa) were used as dispersants. It was observed that the SMANa ionomers improved asphaltene dispersion significantly as the ion content increased and the molecular weight of the SMANa ionomer decreased. Finally, it was found that asphaltene dispersion was more effective when SMANa ionomers were used as asphaltene dispersants, compared to SSNa ionomers. Therefore, it can be concluded that to improve asphaltene dispersion, the acidic copolymers must first be converted to ionomers by neutralization. In addition, when using the ionomer as an asphaltene dispersant, it should be noted that the type of ionic group of the ionomer was more important to control asphaltene dispersion than the MW of the ionomer.