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21 HOW OIL REFINING WORKS

In movies and television shows – Giant, Oklahoma
Crude, Armageddon, Beverly Hillbillies – we have seen images of
thick, black crude oil gushing out of the ground or a drilling
platform. But when you pump the gasoline for your car, you've
probably noticed that it is clear.
And there are so many other products that come from oil,
including crayons, plastics, heating oil, jet fuel, kerosene, synthetic
fibers and tires. How is it possible to start with crude oil and end
up with gasoline and all of these other products? In this chapter,
we'll examine the chemistry and technology involved in refining
crude oil to produce all of these different things.
On average, crude oils are made of the following elements or
compounds:
— Carbon – 84 %;
— Hydrogen – 14 %;
— Sulfur – 1 to 3 % (hydrogen sulfide, sulfides, disulfides,
elemental sulfur);
— Nitrogen – less than 1 % (basic compounds with amine
groups);
— Oxygen – less than 1 % (found in organic compounds
such as carbon dioxide, phenols, ketones, carboxylic acids);
— Metals – less than 1 % (nickel, iron, vanadium, copper,
arsenic);
— Salts – less than 1 % (sodium chloride, magnesium
chloride, calcium chloride).

Crude Oil

Crude oil is the term for "unprocessed" oil, the stuff that
comes out of the ground. It is also known as petroleum. Crude oil
is a fossil fuel, meaning that it was made naturally from decaying
plants and animals living in ancient seas millions of years ago –

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