Crude Oil is Separated into Different Hydrocarbon Fractions Flashcards
What is crude oil?
A mixture of substances, most of which are hydrocarbons - molecules made of just carbon and hydrogen
How are the different compounds separated in crude oil?
By fractional distillation
1) what is done to the oil and what does this do?
Heated until most of it turns to gas - gases enter a fractionating column
What is there in the fractionating column?
A temperature gradient
What happens when the substances that make up crude oil reach a per of the column where the temp is lower than the boiling point?
They condense
What do the longer hydrocarbons have?
High boiling points
What do the longer hydrocarbons do?
Condense and drain out of the column early on, when they’re near the bottom
What do shorter hydrocarbons have?
Lower boiling points
What do shorter hydrocarbons do?
Turn to liquid and drain out much layer on, near to the top of the column where its cooler
What do bubble caps in the fractionating column do?
Stop the separated liquids from running back down the column and remixing
What do you end up with?
The crude oil mixture separated out into different fractions - each containing a mixture of hydrocarbons with similar boiling points
See diagram page 70
Ok
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