The dynamic pendant drop method was employed to better understand the adsorption kinetics at the oil/water interface. Various volume ratios of n-heptane/toluene (heptol) have been chosen as solvents to represent the model of crude oil systems. The results show that an increase in the asphaltene concentration reduces the interfacial tension and this reduction is much more pronounced at higher fractions of n-heptane. The Ward–Tordai short-time model was used to estimate the diffusion coefficient of asphaltenes for dilute solutions of asphaltenes in heptol (up to 0.01 wt %). The results show that the asphaltene adsorbed as monomers onto the interface and the bulk nanoaggregates do not contribute to the adsorption process. Furthermore, the results reveal that the asphaltene diffusion coefficient decreases with increasing its concentration and decreasing solvent aliphaticity. The Langmuir adsorption isotherm was used to study the asphaltene behavior at the oil/water interface and to predict the parameters of adsorption kinetics. It was shown that asphaltenes were adsorbed as monomers onto the interface. The results show that at higher n-heptane fractions, more asphaltene molecules are adsorbed onto the interface. A higher concentration of n-heptane in solvent results in faster and more asphaltene adsorption on the oil/water interface leading to lower interfacial tension and thus promotes emulsification. These findings improve our understanding of adsorption kinetics of asphaltenes at the oil/water interface and find applications in oil/water separation and solvent-aided recovery of heavy oil and bitumen.

Solubility of light n-alkanes in bitumen as well as density and viscosity of the bitumen-rich phase are the necessary data for simulation and study of the solvent-aided thermal recovery processes of bitumen. This paper presents experimental data for MacKay River bitumen with n-alkane solvents (methane, ethane, propane, and butane). The viscosity and density of the solvent saturated bitumen phase are measured to determine the effect of solvent dissolution on the thermo-physical properties of bitumen. The solvent-bitumen system is modelled using the Peng-Robinson equation of state (PR-EoS). Moreover, experimental viscosity and density data of solvent-saturated bitumen are correlated. The effective density and viscosity of the dissolved solvent molecules are obtained using the experimental density and viscosity data for the bitumen-solvent system.

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Solvent-aided bitumen production from oil sands has shown promise as an alternative to thermal recovery methods. Phase behavior studies of solvent/bitumen mixtures are necessary for reservoir simulation of recovery methods, process design and operation of surface facilities, and transportation. Bitumen and heavy crudes comprise a different weight fraction of asphaltene. In this study, the effect of asphaltene on phase behavior, viscosity, and density of solvent/bitumen systems is studied. Ethane (C2H6) and carbon dioxide (CO2) are considered as solvents. Phase behavior studies and property measurements are conducted on solvent/bitumen and solvent/deasphalted bitumen systems. Solubility of C2H6 and CO2 in the original and deasphalted bitumen are measured. The viscosity and density of the liquid phase are also measured by inline viscometer and densitometer at temperature and pressure ranges of 70–130 °C and 2–8 MPa, respectively. The measured data showed that the asphaltene has no significant effect on C2H6 solubility in bitumen. However, the solubility of CO2 in the original bitumen differs from that of the deasphalted bitumen. The significant effect of asphaltene on density and viscosity of bitumen is also quantified. Mixing rules are also employed to estimate the density and viscosity of asphaltene using the density and viscosity of bitumen and deasphalted bitumen.

Solvent-aided thermal recovery processes have recently gained practical and research interests among other thermal recovery methods due to their reduced environmental footprint and superior energy efficiency. One of the main challenges in design of solvent-based methods is selection of an appropriate solvent that maximizes the bitumen and solvent recoveries. This study attempts to introduce dimethyl ether (DME) as a non-conventional solvent for heavy oil and bitumen recovery. To investigate the performance of the proposed solvent, thermophysical properties of DME/bitumen are studied. Vapour-liquid equilibrium measurements including solubility, density, and viscosity are performed at three temperatures (100, 125, and 150 8C) and pressures up to 6 MPa. The results were compared with propane/bitumen and butane/bitumen systems. All the measured properties fall between propane and butane systems. The solubility and density data were fairly represented using PR-EoS with AARDs of 10.3 and 1.43 %, respectively, and viscosity data were correlated applying the Pederson corresponding state model with an AARD of 10.7 %. The results suggest that DME is a suitable substitute for solvents such as propane and butane in solvent-aided thermal recovery of bitumen from oil sands.