Thermodynamic modeling of asphaltene precipitation in pure and mixed solvents with NRTL-SAC

Abstract

Based on the Yen-Mullins model for asphaltene precipitation, a novel thermodynamic framework has been established to model solvent effects on asphaltene precipitation for 13 out of 15 diverse binary solvents with predictive activity coefficient models, i.e., UNIFAC and COSMO-SAC. In this work, a refined version of NRTL-SAC activity coefficient model is used to correlate the onset of asphaltene precipitation in all the 15 binary solvents. The simplicity of NRTL-SAC in representing the wide range of molecules in terms of four conceptual segments and its proven predictive power pave the way to tackle thermodynamic modeling of asphaltene precipitation in petroleum fluids.