BEHAVIOR OF TAR SAND BITUMEN WITH PARAFFINIC SOLVENTS AND ITS APPLICATION TO SEPARATIONS FOR ATHABASCA TAR SANDS

A study was made of the dissolution of tar sand bitumen using low‐molecular‐weight paraffinic solvents at essentially ambient temperatures. The experimental data were obtained using the spinning disc technique, liquid‐fluidized beds, and direct particle‐size analysis of the insolubles. The results are consistent with a mechanism where the paraffins leach the soluble oil from the bitumen and leave behind a porous network of insoluble asphaltenes. This phenomenon of oil diffusing through an asphaltene layer was modeled using Fick's law for unsteady‐state diffusion. An understanding of the mechanism of bitumen extraction with paraffins and also the effect of fluid mechanics in the tar sand system have been applied to obtain a novel separation of deasphalted oil and asphaltenes from Athabasca tar sands. This new separation technique has the potential of simplifying downstream processing for the bitumen and also of avoiding environmental problems associated with the present tar sand extraction technology. Copyright © 1979 Canadian Society for Chemical Engineering