| Description |
The bitumen contained in Utah tar sands represents a significant hydrocarbon resource. Commercial development of this resource has not been realized principally because of the highly viscous nature of these materials. Viscosities of Uinta Basin, Utah bitumens are typically an order of magnitude greater than for the Athabasca, Canada bitumen (1). The Uinta Basin bitumens, which represent over 10 billion barrels, in place (2), are unusual also because they are thought to be of non-marine origin. The differences in origin and geochemical factors between these bitumens and those of marine origin (Tar Sand Triangle, Utah and Athabasca, Canada) has resulted in a bitumen of notably higher molecular weight, but of lower aromaticity. The predominant carbon type present in these bitumens is alicyclic, or naphthenic, carbon. Knowledge of the structural features of Uinta Basin tar sand bitumen prompted us to take a look at the potential of these bitumens as a feedstock for catalytic cracking. It has been known for many years that high molecular weight naphthenic gas oils give high yields of high octane gasoline ; (3). The high average molecular weight (^700), carbon residue (-10%), and nitrogen (~1%) are expected to add some difficulty to the process. However, the theoretical considerations suggest that catalytic cracking may be an attractive alternative to thermal processing as the primary bitumen upgrading process. In this paper, we present the preliminary results of our study of catalytic cracking of an Asphalt Ridge bitumen. Various experimental apparatus were examined to explore the best system for handling these low volatile materials. Product slates are compared with those derived from thermal processing of the same bitumen. |
