Asphaltenes in crude oil and bitumen: Structure and dispersion

Abstract

Crude petroleum is a mixture of compounds boiling at different temperatures that can be separated into a variety of generic fractions by distillation and by fractionation. In fact, such methods provide a better sense of the overall composition of petroleum and the behavioral characteristics. However, petroleum from different sources exhibits different characteristics, and the behavioral characteristics are often difficult to define with any degree of precision. As anticipated and inasmuch as there is a wide variation in the properties of petroleum, the proportions in which the different constituents occur will also vary widely. Thus, some crude oils have higher proportions of the lower boiling constituents, whereas others (such as bitumen, also referred to as natural asphalt) have higher proportions of the higher boiling constituents (often called the {open_quotes}asphaltic components{close_quotes} or {open_quotes}residuum{close_quotes}). It is these higher boiling constituents that often lead to problems during recovery and refining operations. 105 refs., 14 figs., 1 tab.