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Crude Oil Essay

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Crude Oil

Crude oil is a complex mixture of hydrocarbon molecules formed over millions of years when the remains of microscopic sea creatures trapped in sediments were converted by heat and pressure into crude oil.

The most abundant of these mixtures are the ones containing hydrogen and carbon only. These hydrocarbons can take on a number of different forms, i.e. alkanes, alkenes and alkynes. They vary in size and shape and viscosity. By manipulating these chains of hydrocarbons you can create any number of useful substances as they are very adaptable. However there are lots of compounds that also contain some of the following; oxygen, sulphur or nitrogen. The purer hydrocarbon …show more content…

These separate fractions can now be distilled again if necessary to get the useful materials out of the fraction. The fractions are separated as follows:

· The crude oil is vaporised by heating it before it reaches the fractionating column

· The vaporised crude oil is feed into the bottom of the column.

· Steel trays divide the column and the crude oil vapour rises up through holes in the trays.

· The temperature gradient between the bottom of the column to the bottom (progressively cooler upwards) means that as the vapour passes through a tray it comes into contact with the cooler liquid on that layer and some of the hydrocarbon chains condense.

· This leaves the rest of the vapour to continue rising until they reach their respective levels.

The distillation continues as above until 40 or 50 condenses have taken place then there is enough of each level to remove the separate fractions. In industry there is a careful balance to the amount of crude oil allowed in at the bottom of the tower at a time so that the fractions can be removed repeatedly without interrupting the process.

The fractions are removed in the following order from the bottom (hottest) and the list also shows what can be done with each substance or how it can be used.

Heavy Petroleum Oil

These consist of simple alkanes with no more than 4 carbon atoms in a chain. They are used as a fuel

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