Fractional Distillation of
Crude Oil
By Blake Turner – Year 11
Fractional Distillation of Crude Oil
Introduction
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 -- most places you can find crude oil were once sea beds. Crude oils vary in colour, from clear to tar-black, and in viscosity, from water to almost solid.
On average, crude oils are made of the following elements or compounds: * Carbon - 84% * Hydrogen - 14% * Sulphur - 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)
The Process
Fractional Distillation
The oldest and most common way to separate things into various components (called fractions), is to do it using the differences in boiling temperature. This process is called fractional distillation. You basically heat crude oil up, let it vaporize and then condense the vapour
The various components of crude oil have different sizes, weights and boiling temperatures; so, the first step is to separate these components. Because they have different boiling temperatures, they can be separated easily by a process called fractional distillation.
The steps of fractional distillation are as follows:
1. You heat the mixture of two or more substances (liquids) with different boiling points to a high temperature. Heating is usually done with high pressure steam to temperatures of about 1112 degrees Fahrenheit / 600 degrees Celsius.
2. The mixture boils, forming vapor
Bibliography: http://science.howstuffworks.com/environmental/energy/oil-refining4.htm http://www.aip.com.au/industry/fact_refine.htm www.theoildrum.com/node/6089 en.wikipedia.org/wiki/Separation_process