Thermodynamic and kinetic modelling of asphaltene precipitation from heavy oils and bitumens

Abstract

With the increasing use of bitumens as fuels and chemical feedstocks, it is important to understand how bitumens behave under production and processing conditions. Due to their high viscosity, bitumens cannot be produced by conventional means, necessitating the use of more sophisticated thermal or solvent recovery techniques. It has been observed, however, that the diluents used in the petroleum industry can cause asphaltene deposition from bitumens. A scanning laser particle analyzer is employed to study how asphaltenes are affected by different solvents, thermodynamic conditions and external factors including agitation, shearing and excess oxygen. It was determined that asphaltene particles form extremely quickly, are very stable, and are affected to certain extents by different solvents in varying concentrations. A microvideo camera was also used to view the asphaltene particles and it was discovered that they are not necessarily spherical in nature.