Migration of Fine Solids into Product Bitumen from Solvent Extraction of Alberta Oilsands

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• 作者：Hossein Nikakhtari ; Sebastian Wolf ; Phillip Choi ; Qi Liu ; Murray R. Gray
• 刊名：Energy & Fuels
• 出版年：2014
• 出版时间：May 15, 2014
• 年：2014
• 卷：28
• 期：5
• 页码：2925-2932
• 全文大小：360K
• 年卷期：v.28,no.5(May 15, 2014)
• ISSN：1520-5029

文摘

The extraction of bitumen from the oilsands using solvents has the potential to avoid the environmental problems with wet tailings associated with water-based extraction technology. One of the key performance parameters for this technology is the concentration of fine solids in the recovered bitumen. In this study, the concentration and properties of the fine solids in cyclohexane-extracted bitumen were examined as a function of the water content of the ore. Total water contents from 3.4鈥?3.4 wt % gave the lowest concentrations of fine solids in the bitumen, ca. 0.2 wt % of the initial mass of a low-fines content ore. Higher fine solids contents in the bitumen were observed with water concentrations outside this range and with higher concentrations of fine solids in the initial oilsands ore. The fine solids exhibited a distribution of surface properties, and the most hydrophobic, carbon rich solids were carried into the bitumen even under the most favorable conditions. When the bitumen was more contaminated with fine solids, due to higher fines in the ore or lack of water to bind the fines to the sand, the carbon content of the fine solids decreased. The majority of the carbon in the fine solids was organic material due to bitumen and surface adsorbed components. Despite carbon contents over 20 wt %, XPS analysis showed significant surface silicon and aluminum, and contact angles were in the range of 80鈥?8掳, consistent with partial organic coating of the mineral particles. Characterization of the fine solids by SEM, particle size, and mineralogy suggested that the migration of the fine solids into the bitumen, versus remaining with the coarse sand, was significantly affected by the organic surface deposits on the particles.