Chapter 2: Mineral Base Oils

Abstract

IN THIS CHAPTER WE DESCRIBE PETROLEUM composition and the oil field and refinery chemicals that are used to facilitate petroleum drilling to extract crude petroleum from beneath the earth's surface and refine it to yield value-added products, such as fuels, lubricant base stocks, and petrochemicals. The chapter also describes many of the refinery processes in some detail to explain the manner in which the hydrocarbon cuts from petroleum with suitable properties for use as lubricant base stocks are obtained. Commonly referred to as mineral oils, they are the cheapest and the most abundant base stocks available and therefore are often used to formulate lubricants. Discussion also includes the desirable properties of the mineral oils that are critical to formulating a quality lubricant. Untreated or nonformulated lubricants (mineral base oils and synthetic base stocks) do not possess the necessary properties to perform effectively in todays demanding lubricating environments. To function properly in such environments, base fluids need the help of chemicals, called additives. Additives improve the lubricating ability of the base oils either by enhancing the desirable properties already present or by adding new properties. Most of today's lubricants are formulated lubricants, and additives are their integral part [33]. The world consumption of lubricant additives has increased from 2.6 million metric tons (5.7 billion lb) in 1997 to about 3 million metric tons (̃6.6 billion lb) in 2006. The consumption is expected either to plateau or grow slowly in North America and Western Europe, which consume the largest share of the total. The developing economies of Asia, such as India and China, and of Latin America, such as Brazil, Chile, and Argentina, are expected to see a faster growth.