Answer:

Essential oils are highly concentrated aromatic compounds derived from plants. They are commonly used in various applications such as aromatherapy, cosmetics, and food flavoring. To obtain pure and high-quality essential oils, they need to undergo a purification process. The most common method used for purifying essential oils is steam distillation.

Steam Distillation:
Steam distillation is a process that involves the separation of volatile compounds from a mixture using steam. It is the preferred method for purifying essential oils because it allows for the collection of the volatile compounds without destroying their chemical composition.

The process of steam distillation can be divided into the following steps:

1. Steam Generation:
Water is heated to produce steam. The steam is then passed through the plant material containing the essential oil compounds.

2. Vaporization:
As the steam passes through the plant material, the heat causes the volatile compounds to vaporize. These vaporized compounds mix with the steam.

3. Condensation:
The steam and vaporized compounds are then cooled down in a condenser. The condenser cools the steam and converts it back into liquid form. The volatile compounds, which are insoluble in water, separate from the water and collect as a layer on top.

4. Separation:
The collected mixture of essential oil and water is transferred to a separator, where the water and essential oil are separated. Since essential oils are lighter than water, they float to the top and can be easily separated from the water.

5. Storage:
The purified essential oil is then stored in dark glass bottles to protect it from light and oxidation, which can degrade its quality.

Advantages of Steam Distillation:
- Steam distillation is a gentle extraction method that helps preserve the natural composition and aroma of essential oils.
- It is a relatively simple and cost-effective process.
- The use of steam reduces the risk of overheating and degradation of the volatile compounds.

In conclusion, steam distillation is the primary method used for purifying essential oils. It allows for the separation of volatile compounds from plant material without altering their chemical composition, resulting in pure and high-quality essential oils.