C7 - Fractional Distillation & Petrochemicals

What must we do in order for the hydrocarbons in crude oil to be useful?

We have to separate them using fractional distilations

During fractional distillation what is crude oil separated into?

Crude oil is separated into fractions

What do fractions contain?

Hydrocarbons with a similar number of carbon atoms

Where does fractional distillation take place?

In very large columns found in oil refineries

What are the steps of separating hydrocarbons into fractions using fractional distillation?

-Firstly, the crude oil is heated to a very high temperature, which causes the crude oil to boil.

-All of the hydrocarbons evaporate and turn into a gas.

-The crude oil vapour is now fed into the fractional distillation column; the column is hotter at the bottom and cooler at the top.

-The hydrocarbon vapours now rise up the column.

-Hydrocarbons condense (turn back to liquid) when they reach their boiling point.

-The liquid fractions are then removed.

-The remaining hydrocarbons continue moving up the column, and these now condense when they reach their boiling points

What type of boiling points do very long chain hydrocarbons have?

very high boiling points

How are long chain hydrocarbons removed from the fractions?

From the bottam of the column

What type of boiling points do very short chain hydrocarbons have?

Low boiling points

How are short chain hydrocarbons removed from the fractions and why?

These do not condense, so they are removed from the top of the column as gases

What are some fractions used as?

Fuels

Give 5 fuels produced from crude oil

-Petro

-Diesel oil

-Kerosene

-Heavy fuel oil

-Liquefied petroleum gas

What are some fractions used as apart from fuel?

Feedstock for the petrochemical industry

What is a feedstock?

A chemical that is used to make other chemicals

State 4 products feedstock fractions are used to make?

Solvents, Lubricants, Detergents, Polymers (silly lions dance proudly)