並列摘要
Due to the increased demands of gasoline and distillates in quality and quantity, the upgrading of heavy oil becomes more and more important both technically and economically. The principles of heavy oil upgrading are impurity removal, hydrogen content enrichment and molecular size reduction, that is cracking. Based on these principles, major upgrading processes are developed, namely, thermal cracking, catalytic cracking and hydroprocessing. The important features and the developing trends of the processes are discussed. The key to process selection is economic evaluation. A typical procedure for process evaluation is described with emphasis on the key economic parameters. In assessing the upgrading processes using the economic procedure, it is shown that: ‧ The nature of heavy crude itself is the most important factor in selecting the best upgrading technology. ‧ The capital cost is the key economic factor in selecting heavy crude upgrading technology. ‧ Increase in conversion level improves the economics of crude upgrading technology.