ABSTRACT
A good working knowledge of the basic chemistry and operations of crude oil refining should enable engineers, chemists, technologists, and oil refining executives to better manage their oil refining assets. This chapter provides basic chemical composition, chemicals, and some of the key contaminants in crude oils that could negatively impact oil refining processes and equipment. The main hydrocarbon types present in crude oils are paraffins, naphthenes, and aromatics. Speight discussed a crude oil from Pennsylvania in the United States that was determined to contain up to 3 wt. % of olefins in the crude oil and in the distillate fraction of that crude. Sulfur can be as high as 6 wt. % of some crudes, and total metals could be as high as 0.1 wt. %. Heteroatoms negatively impact the performances of catalysts in hydroprocessing units. Oil fractions produced from coking units typically contain higher percentages of heteroatom contaminants and unsaturated compounds relative to similar straight-run fractions from crude distillation units.
