Hydroprocessing of heavy residual oil: Opportunities and challenges

Recently, significant changes in petroleum sources have been observed where light crude sources are becoming heavy or extra heavy, containing a large number of contaminants (S, N, metals, asphaltene, etc.), and producing a significant fraction of the bottom of the barrel (residue) after distillation. Thus, the future crude slate is a vital issue facing refiners to invest strategically in processing larger quantities of sourer crude. Due to the feedstock, refinery process operations must advance and include next-generation processes and catalysts to fulfill the demand and supply. The qualities of these products primarily meet or satisfy stringent environmental regulations. On the other hand, traditional light crude oil refineries have seen drastic changes into heavy crude oil, which present enormous challenges to the refining industry to process heavier crude oils. The global trend indicated that the world oil refining industry has to face several challenges in demand as well as supply. At the same time, refineries are expected to be under a great deal of pressure to accomplish the market demand for high-quality fuels (i.e., gasoline and diesel). The global demand for diesel fuels is increasing, while fuel oil demand is decreasing. The fuel composition and their efficiency (energy content) remain a decisive factor for the price and the communally acceptable parameter. This review will focus primarily on the relationship between the various parameters of composition, physicochemical properties of crude oil, and their impact on hydroprocessing.