| The demand for accurate bitumen + pentane mass transfer data was the main motivation behind this research. Difficulties such as complex phase behaviour, high viscosity and opacity of the hydrocarbon invariably lead to failure of conventional techniques to measure mass transfer coefficients involving heavy oils. To address this issue, X-ray transmission tomography has been employed for such measurements. The initial set of experiments in this study measured the free mutual diffusion coefficient of pentane + Athabasca bitumen, as well as pentane + atmospheric residue. In addition, forced mass transfer between pentane and both bitumen and atmospheric residue was studied. Forced mass transfer between pentane and these two heavy oils followed a similar pattern when normalized and the pattern is consistent with prevailing understanding. However, mass transfer rates between pentane and Athabasca atmospheric residue are one order of magnitude smaller than for the corresponding bitumen case. Impacts on the effectiveness of proposed production and refining processes are discussed. |
