Integrated extraction and low severity upgrading of oilsands bitumen by activated natural zeolite catalysts

Inexpensive natural zeolites such as chabazites and clinoptilolites, found in abundance in multiple global deposits, can offer an effective, economical and environmentally friendly alternative to current methods of oilsands bitumen upgrading. This study shows that water added (∼3 wt.% of feed) natural zeolite catalysts, can effectively convert up to ∼81% of the residue within oilsands bitumen in a stirred batch system under relatively low severity conditions. The reactions produce very high total liquid yields (up to ∼96%), significant amounts of which are residue-free (up to ∼71%). The resulting liquids have lower viscosity, boiling point distribution and average molecular weight than the bitumen from both raw samples and uncatalyzed oilsands treated thermally under the same conditions. These reactions, particularly when conducted under low severity conditions, produce little gas and result in minimal coking. In addition, the, natural zeolite-processed bitumen is less aromatic than thermally processed bitumen and contains much lower concentrations of heteroatoms (nitrogen, sulfur) and heavy metals (vanadium) compared to raw and untreated bitumen. Based on our results, we envision an alternative, more effective and environmentally friendly, low temperature, integrated extraction and upgrading process for oilsands bitumen that uses water-enhanced natural zeolites, requires fewer steps and improves pipeline transportation.