Impacts of physico-chemical properties of asphaltene aggregates on optimization of the thermal de-asphaltene process

Abstract

The physico-chemical properties of asphaltene were studied at temperature range of 80–150 °C to optimize asphaltene aggregation and separation from crude oil in the thermal de-asphaltene process without adding n-alkane. The particle size obtained through dynamic light scattering (DLS) indicate that increasing temperature up to 120 °C led to an increase in the physical dimensions of the asphaltene particles, while a decrease in size is noticed at temperatures above 120 °C. The structural molecular parameter of asphaltene indicate that the maximum and minimum aromaticity of asphaltene aggregates occur at 80 and 120 °C, respectively. Increasing the size of the particles and decreasing the aromaticity, as well as raising the efficiency of asphaltene thermal isolation indicate a growth in asphaltene particles at a temperature rise from 80 to 120 °C. All the obtained data suggest an optimal temperature of 120 °C for the thermal de-asphalting of this test sample. The surface morphologies of asphaltene particles at this optimal temperature were assessed by scanning electron microscopy (SEM). © 2016 Elsevier B.V.