Liquid–Liquid Equilibrium Studies of Multicomponent Diluent/Bitumen System with Application to Solvent-Aided In Situ Bitumen Recovery

• Published in: Energy & fuels 2023-07, Vol.37 (14), p.10275-10286
• Main Authors: Khan, Mohammad Shah Faisal, Hassanzadeh, Hassan
• Format: Article
• Language: English
• Subjects: Traditional Fossil Fuels
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.3c01719

Although conventional thermal methods have been widely used for bitumen recovery, solvent-based or solvent-assisted techniques have emerged as viable, greener alternatives. Understanding the liquid–liquid equilibrium (LLE) of multicomponent diluent/bitumen systems is crucial in designing and optimizing oil recovery processes. Despite the availability of vapor–liquid equilibrium (VLE) data for multicomponent/bitumen in the literature, there is a lack of LLE data and predictive models for these mixtures. These data are essential for designing and optimizing oil recovery processes. This study presents the LLE measurements of multicomponent/bitumen mixtures in the temperature range of 295–352 K and a constant pressure of 2.159 MPa, applicable to in situ bitumen recovery processes. The measured thermophysical properties include the density and viscosity of the light phase. The measured density and viscosity data are modeled using the Peng–Robinson equation of state (PR-EoS) and the modified Pederson model, respectively, with average absolute relative deviations (AARDs) of 0.4 and 6.1%. Additionally, a combination of gas chromatography (GC) and gel permeation chromatography (GPC) was utilized to obtain detailed molecular weight and compositional analyses of the heavy and light cuts. In summary, the findings of this study improve our understanding of the LLE of multicomponent solvents/bitumen systems and offer valuable information for developing and improving solvent-assisted oil recovery processes as alternatives to energy-intensive conventional thermal recovery methods.