We can obtain different gases from air by fractional distillation of liquid air.
Air is a gaseous mixture that is homogeneous. It is made up of various amounts of gases such as nitrogen, oxygen, carbon dioxide, argon, and others. We need to use special separation methods since it’s a homogeneous mixture. The process of fractional distillation is used to extract various components from the air.
Fractional distillation is a process of separation in which the difference in boiling points of components is used to distil a liquid mixture into fractions. The liquefaction of air is the first step in the process.
Step 1 – Conversion of air into liquid air
Liquid air is created by converting gaseous air into liquid air. This is achieved under extreme pressure. The air is compressed under high pressure and then cooled by lowering the temperature. As a result, liquid air is generated.
Step 2 – Fractional Distillation
The liquid air is then passed through the fractional distillation column. The liquid air is allowed to warm up in this area. The fractionating column’s bottom is colder than the top. Depending on its boiling point, each gas begins to separate at various temperatures.
The boiling point of nitrogen is -196°C, while the boiling point of oxygen is -183°C. The nitrogen gas would begin to escape and be collected via the outlet. In the fractionating column, liquid oxygen will be collected.