Impact of Crude Oil Quality on Downstream Refining Processes

Worldwide petroleum refining industry is entering into a significant era due to the depletion of light crude. The light crude sources are turning into heavy or extra heavy, which contains large amount of contaminates (S, N, metals, asphaltene etc.) and produce large fraction of residue. Thus, future crude slate is a key issue facing refiners to invest strategically in order to process larger quantities of sourer crude. Refinery operations have to evolve and include next-generation processes and catalysts to fulfill the demand for high-quality transportation fuels. Since the quality of these products has to be improved to satisfy stringent environmental regulations, refineries, which have been traditionally processing light crude oils, face drastic changes in petroleum feed properties, which stubborn great challenges to refining industry to process heavier crude oils. The global trend indicated that the world oil refining industry has to face several challenges for demand as well as supply. At the same time refineries are expected to be under great deal of pressure to accomplish the market demand of high quality fuels (i.e., gasoline and diesel). The world demand for diesel fuels is increasing while fuel oil demand is decreasing. Therefore, the need to convert heavy, extra heavy or residue fraction into valuable products (middle distillate) will increase in order to satisfy market demand. This paper will be focus on examples of the quality parameters that is impending due to the quality of crude oil and presence of high levels of impurities during the processing poor feedstocks in processes such as diesel and resid hydrotreating units. In addition, the understanding of such feedstock by detailed characterization at their molecular level and its impact on the processing will be also highlighted.