Experimental evaluation of asphaltene dispersants performance using dynamic light scattering

Abstract

In this study, the asphaltene particle aggregation process is studied and effects of asphaltene concentration, n-heptane to toluene volume ratio, type and concentration of asphaltene aggregation inhibitor are investigated on onset of precipitation and asphaltene particle size distribution (APSD). The measurement of APSD is performed through dynamic light scattering technique. The results show that the concentration of asphaltene doesn't have significant effect on the onset point; however, it leads to form bigger particles. An increase in n-heptane volume ratio leads to increases the asphaltene particles size where 5% of particles are bigger than 6 μm after 40 min. Dodecyl benzene sulfonic acid component displaces the onset point reasonably and causes 7% rise in the amount of required n-heptane. Dodecyl resorcinol has the best performance at concentration of 50 ppm as an asphaltene dispersant and causes required n-heptane volume increment of 2%. It reduces the asphaltene particles size significantly and delays the asphaltene particles agglomeration process of about 30 min.