II.2.1.2. Distillation
Distillation is the separation of liquid components from a homogeneous mixture based on their different boiling points.
During distillation, two physical phenomena occur: vaporization, followed by condensation.
If there is a mixture of water and alcohol in the flask, by heating, the temperature will rise, and when it reaches 78 °C, the alcohol begins to boil.
Throughout the boiling of the alcohol, the temperature remains constant at 78 °C. Alcohol vapors reaching the refrigerant are cooled and condense.
When the temperature starts to rise above 78 °C, the alcohol has separated from the water and the distillation stops. The water separated from the alcohol.
In general, the component parts of the mixture have boiling points that do not differ by more than 25 °C from each other at one atmosphere pressure. On the other hand, if the difference between the boiling points is greater than 25 °C, a simple distillation can be used to separate the components.
1. Obtaining distilled water (chemically pure), used in laboratories, industry, pharmacy.
2. Obtaining alcoholic beverages in industrial installations with alembic.
3. Through the fractional distillation of oil, in petrochemical refineries, propane, butane, gasoline, lamp oil, diesel, fuel oil are obtained. These products of oil distillation are used as fuels, to obtain plastics, medicines, artificial rubber, artificial fibers, detergents, insecticides, pesticides, etc.
4. Fractional air distillation with separation of nitrogen from oxygen. Consider a distillation flask containing a liquid mixture of oxygen (the heavy component) and nitrogen (the light component). If the liquid mixture is heated it will begin to boil, producing vapors that contain more nitrogen (the light component) than the original liquid. These nitrogen-rich vapors condense in a condenser.
