Factors influencing non-aqueous extraction process of bitumen to mitigate the environmental impacts

•Non-aqueous extraction process and engineering unit were developed, which uses much less water and reduce the release of major hazardous chemicals to oil sands tailings.•The Factors influencing the process are studied: grades of ores (high, medium and low-grade); different solvents (toluene, pentane and other mixed solvents), and different S/Bs were studied.•The higher-grade ore contains more heavy bitumen, the higher mitigating of the environmental impacts.•The recovery rate of cyclopentane is higher than that of toluene.•Mitigating the environmental impact effects were studied experimentally, efficiency of bitumen recovery was able to reach over 99 % wt %. Environmental pollutants' transport through tailing extraction process is a big challenge. Hazardous materials in tailings ponds increase with high negative environmental impacts. In this paper, a new type of bench no-water-extracted bitumen process was developed. Factors such as three oil sand ores, namely high, medium, and low-grade in the Athabasca deposits have been exposed to five different light hydrocarbon solvents. The bitumen recovery efficiency of the novel system was investigated with respect to solvent-to-bitumen ratios (S/Bs) as well as solvent and ore properties. The results showed that this novel bench-scale non-aqueous extraction process could significantly reduce water consumption and improve solvent recycling and reduce the release of major hazardous chemicals to oil sands tailings water. The new solvent recovery and bitumen quality for all treated ores were as good as the outcomes from hot water leaching and naphtha froth treatment. When low boiling point solvents (especially cyclopentane) are used to treat high grade ores, the efficiency of bitumen recovery was able to reach over 99 % wt % (by weight %). At the same time, the solvent loss rate could be controlled below 4 barrels (bbl) of solvent per 1000 bbl of extracted bitumen (0.4 %). This indicates the evident effectiveness of non-aqueous extraction of bitumen to mitigate the environmental impacts.