ABSTRACT
Heavy oils and residua are those feedstocks that are less desirable for conversion to liquid fuels. However, the depletion of the reserves of conventional petroleum has brought about an interest in the conversion of the heavier feedstocks. It has also been realized that any degree of self-sufficiency would necessitate the use of heavy oil and bitumen. There also has been a concerted effort to focus on bottom-of-the-barrel processing in which residua are converted to distillate liquid fuels. In the past, such materials had more often been used for road asphalt and refinery fuel.
