Crude Oil

“Crude Oil”

• Crude oil is a fossil fuel formed from the remains of marine animals and plants that died millions of years ago; high pressure and heat in the Earth’s crust converted these remains into the mixture of hydrocarbons we call crude oil.

• Hydrocarbons are the main components of crude oil. These are organic compounds made up of only hydrogen and carbon atoms. The nature of the hydrocarbon (including its size, structure, and intra- and inter-molecular forces) dictates oil’s physical and chemical properties.

• Crude oil is a mixture of hydrocarbons varying in size from one to hundreds of carbon atoms. The number of carbon atoms in a molecule determines which ‘fraction’ it belongs to.

• Fractions with fewer carbon atoms (1-4), such as methane and propane, are gases at room temperature while fractions with great number of carbon atoms (100+) are solid and are used in materials like asphalt.

• Crude oil is not very useful in its raw state. It must undergo a process called fractional distillation to be useful.

• In fractional distillation, the crude oil is heated until it turns into a gas. The gas then rises through a column (also known as fractionating tower), cooling as it goes up. Different hydrocarbons condense at different heights depending on their boiling points, enabling them to be collected and separated.

• The separated fractions are then often treated further to make them more useful – this could include cracking (breaking long-chain hydrocarbons into shorter ones) or reforming (changing the structure of the hydrocarbon molecule).

• Crude oil and products obtained from it are mostly used as fuels. For example, petrol and diesel fuel for vehicles, and kerosene for jet engines. They are also used to manufacture a wide variety of chemicals and materials like plastics.

• Crude oil is not a renewable resource; it can take millions of years to form. The usage of crude oil also contributes to environmental problems such as global warming and air pollution due to the emission of greenhouse gases and other pollutants during combustion.

• Alternatives to crude oil are being intensively researched, including biofuels, hydrogen fuel, and electric power for transport. Laws and policies are being developed to encourage the use of such alternatives and reduce our dependence on crude oil.

Remember, understanding the properties and uses of crude oil, as well as the process of fractional distillation, is essential. Knowledge of the environmental impact and alternatives to crude oil also come up in the exam questions regularly.