With origin in the Latin word destillatio, distillation is he process and the result of distilling. This verb refers to filter or to do what drip a liquid, or to achieve the separation of one component from others through the application of hot.
For instance: “The distillation of whiskey began to develop at the end of the 15th century”, “In the process of obtaining fuel, the distillation of oil is very important”, “The teacher of Chemistry he taught us what distillation consists of “.
The notion of distillation is often used to name the procedure that allows separate substances that form a mixture, through its condensation or its vaporization. Thanks to the different points of condensation and boiling of substances, distillation makes it possible to distinguish between liquefied gases, solids that were dissolved, and liquids.
According to how the process develops, it is possible to speak of different types of distillation:
It is used when there is only one volatile substance in the mixture of products liquids, or when there is more than one but the difference between the boiling point of the liquid with the highest volatility and that of the rest equals or exceeds 80 ° C. This procedure results in a single product, since: it is the amount of components that were in the original mixture; one of the components was considerably more volatile than the rest. Simple distillation requires a vacuum adapter and a vacuum system.
Within this type of distillation, we can distinguish between the following two classes:
* at atmospheric pressure: is carried out at Pressure environmental. It is used mainly in cases in which the boiling temperature of the product is lower than that of its chemical decomposition;
* at reduced pressure: it is achieved by reducing the pressure in order to lower the boiling point of the component that we wish to subject to distillation. It is usually used when the boiling point of the product is higher than the temperature of its chemical decomposition.
It is used when the boiling points of the volatile substances in the liquid mixture have a difference of less than 80 ° C. When the mixture is heated, the steam It acquires more wealth in the element of greater volatility, a property that is used to divide the liquid compounds. This type of distillation is characterized mainly by requiring a fractionation column. It can be carried out at reduced or atmospheric pressure, as is the case with simple distillation.
It is used to purify or isolate compounds whose boiling point is very high, through the use of temperatures that do not exceed 100 ° C. This type of distillation is very convenient for dealing with substances that have a boiling point well above 100 ° C and that never decompose beyond that temperature.
Thanks to steam distillation it is possible to separate substances that are not soluble in H2O, as well as those with a slight volatility from other non-volatile ones. An excess of Water to the mixture in which the product to be separated is found. For this procedure, two flasks are used (glass or glass vessels whose shape is usually spherical and ends in a straight and narrow cylinder): the distillation flask, in which the compounds soluble in hot water and / or volatile remain; and the collector, which recovers the insoluble in water and the volatiles. An extraction is carried out to isolate the organic compounds from the collecting flask.