Chapter 10 Effects of Asphaltene Precipitation on the Size of Vanadium-, Nickel-, And Sulfur-Containing Compounds in Heavy Crude Oils and Residua

Abstract

Publisher Summary This chapter addresses the question of whether the concept of asphaltenes is appropriate to use when discussing certain aspects of petroleum-chemistry characterization, process monitoring and design—where size is an important factor. Although asphaltene precipitation concentrates the metal compounds, it tends to increase the average molecular size of the metal-containing compounds through agglomeration. This can cause analysis difficulties when size-related properties, for example, catalyst pore-metal-containing molecule interactions are being considered. Although the asphaltene precipitation does concentrate the sulfur-containing compounds to some extent, there is little evidence that the precipitation increases the average size of these compounds through agglomeration. The asphaltene precipitation, however, does separate some sulfur-containing compounds from the resin fraction. This could cause analytical difficulties if not accounted for, because these sulfur containing compounds in the resin fraction can have similar structures to those of the asphaltenes.