Organic Chemistry: Crude Oil

Crude oil, commonly referred to as petroleum, is a complex mixture of hydrocarbons and other organic compounds.
It ranges from low molecular weight hydrocarbons like methane and ethane, to complex high molecular weight compounds.
Crude oil is believed to have been formed from the remains of tiny marine plants and animals (plankton) that died millions of years ago.
These organic remains were then subjected to intense heat and pressure under the seabed over millions of years, resulting in the formation of crude oil.

Crude oil can be separated into different components known as petroleum fractions, using a technique called fractional distillation.
Fractional distillation takes advantage of the different boiling points of the hydrocarbons in crude oil.
The separation occurs in a fractioning column, which is hottest at the bottom and coolest at the top.
The hydrocarbons condense at different levels, known as fractions, in the column depending on their boiling points. The fractions collected at the top of the column contain smaller hydrocarbons with lower boiling points, while fractions at the bottom contain larger hydrocarbons with higher boiling points.

The smallest hydrocarbons (1-4 carbons) found in the gas fraction are used as fuel gases in homes and industry.
The fraction containing 5-12 carbon atoms is used to make gasoline.
Fractions with hydrocarbons ranging from 12 to 16 carbons are used to produce diesel fuel and kerosene.
Finally, the largest hydrocarbons with greater than 20 carbons, found in heavy fuel and bitumen fractions, are used for ship fuel and road coverings respectively.

The burning of fossil fuels, including the hydrocarbons in crude oil, results in the release of carbon dioxide, a greenhouse gas.
The excessive amount of carbon dioxide in the atmosphere contributes to global warming and climate change.
In addition, oil spills, both land and sea, are the result of improper handling or accidents involving crude oil, causing devastating environmental damage and loss of life.

Crude oil is a non-renewable resource, which means once used, it cannot be replaced, and hence there are concerns about what will happen when this resource is exhausted.
The search for alternative energy sources is a significant scientific and environmental challenge. Examples of these alternatives include hydrogen fuel cells, solar energy, and wind energy.
The development and enhancement of these alternative, renewable energy sources, along with more responsible use of existing fossil fuels, are key strategies to a sustainable energy future.