Organic Chemistry

Carbon compounds as fuels and feedstock

Crude oil, hydrocarbons and alkanes

• Crude oil is a fossil fuel that comes form the remains of ancient biomass (mainly plankton), and is formed over a billion of years due to the effects of high pressures and temperatures

• Crude oil is mostly made out of hydrocarbons (substances that only contain hydrogen and carbon) called ALKANES (saturated meaning they only contain single bonds)

• the general formula for the homologous series (each member has the same functional group, general formula and similar chemical properties) of alkanes is C_n H_2n+2

• The first four alkanes are methane, ethane, propane and butane

  

Fractional distillation and Petrochemicals

• crude oil is seperated into different fractions using fractional distillation, which consists of :

1. Heating crude oil and waiting for it to vaporise

2. the vapours of the crude oil enter the fractionating column which has a temperature gradient

3. The vapours of hydrocarbons with high boiling points condense at the bottom of the column

4. The vapours of hydrocarbons with lower boiling points rise up the column and condense at the top 

• A fraction is a group of hydrocarbons of similar chain lengths