5 Characteristics of distillation

5 Characteristics of distillation
Distillation is a separation process in which a mixture of liquids or liquid components is purified and separated from different boiling points by vaporization and selective condensation.

The distillation is carried out on a team called a distiller, consisting of a closed container that is heated, and a condenser that cools the generated steam.

The mixture of liquids is heated until the components with the lowest boiling points begin to evaporate and form steam, which is transported through a tube to the capacitor.

In the capacitor, the vapour is cool and condensed back into liquid, and the condensed liquid is collected in a separate container.

Distillation is commonly used in the chemical and pharmaceutical industry to purify and separate components of mixtures such as solvents, chemicals, petrochemicals and medicines.

It is also used in the production of alcoholic beverages, such as the distillation of wine to produce brandy or whisky.

What is distillation?

Distillation is the process of separating a mixture based on significant differences in vapor pressure and boiling point.

Distillation or refining is a mixture separation process that is based on differences in the boiling points of the components that make up the mixture.

Apart from that, distillation is the process of heating a liquid or solid object until it turns into steam which is channeled into a separate vessel which is then condensed with a coolant.

Features

Some characteristics of the distillation are as follows:

  1. It is based on the difference of boiling points: The distillation is based on the difference in boiling points of the components of a liquid mixture. Each component has a different boiling point, and can therefore be separated by vaporization and selective condensation.
  2. It’s a process of physical separation: Distillation is a process of physical separation that doesn’t involve chemical reactions. It is used to separate mixtures of liquids that cannot be separated by other means.
  3. It is used to purify liquids: Distillation is used to purify liquids, eliminating contaminants and other unwanted components. The distilled liquid is usually purer and of higher quality than the original mixture.
  4. It can be used at the industrial and laboratory level: Distillation is used both at the industrial and laboratory levels. Laboratory distillers are smaller and designed to process smaller amounts of liquids.
  5. It is a widely used technique: Distillation is a widely used technique in different industries, such as chemistry, pharmaceutical, food and beverage. It is a very versatile technique that can be adapted to different situations and requirements.

Types of distillation

There are several types of distillation that are used to separate and purify different types of liquid mixtures. Some of the most common distillation types are:

  • Simple distillation: is the most basic type of distillation and is used to separate liquids with different boiling points. It consists of heating the liquid mixture until the component evaporates with the lowest boiling point, which is then condensed and collected in a separate container.
  • Fractional distillation: is used to separate liquids that have very close boiling points. It consists of repeating the distillation process simply several times, using a fractionation column to separate the most volatile components.
  • Vacuum distillation: is used to separate liquids that have very high boiling points. It consists of distilling at reduced pressures, which reduces the boiling point of the components and facilitates their separation.
  • Steam drag distillation: is used to separate liquids that are insoluble in water, but can be separated by vaporization. Water is added to the mixture and heats, generating steam that drags the most volatile components and separates them into a capacitor.
  • Azeotropic distillation: is used to separate liquids that form an azeotropic, i.e. a liquid mixture with a constant boiling point. It consists of adding a third component to the mixture, which forms a different azeotropic and allows the separation of the original components.

Distillation process equipment

The equipment required in the distillation process varies, depending on the type of distillation. Here’s the explanation:

Simple distillation

Simple distillation requires a series of tools that are arranged without the need to use a distillation column.

The distillation equipment used is:

  • Clamp
  • Thermometer
  • distillation flask
  • Distilled solution
  • Bunsen or other heat source
  • Cooling
  • Container

Things that need to be considered when using a simple distillation tool are:

  • It’s best to arrange the tools from left to right.
  • Always add boiling stones to the distillation flask to avoid bumping.
  • It is best to submerge the distillate container in an ice bath to prevent the formation of steam, especially for toxic or flammable compounds.
  • The distillation flask used must be adjusted to the amount of mixture to be distilled.
  • Adjust the heating to maintain a distillation speed of one drop per second.
  • Do not use a beaker to hold the distillate.

Fractional distillation

In contrast to simple distillation, fraction distillation requires a device called a fraction column.

In order to achieve high fractionation efficiency, it is best to use a vacuum jacketed column. If this tool is not available, it is best to wrap the column using aluminum foil to minimize heat loss.

The provisions that apply to simple distillation also apply to fractional distillation.

If there are several fractions that you want to accommodate, you can add a container so that you don’t need to stop the distillation process when you want to accommodate different fractions.

Distillation process

The distillation process consists of several stages, namely changing a compound into its vapor form, condensing the vapor formed into liquid again, and collecting the condensation results into a container.

This process is able to separate mixtures with different boiling points. Apart from that, the distillation process can also separate compounds that are more easily volatile (volatile) from compounds that are difficult to evaporate (not volatile).

The following is an illustration of the process of separating spirit mixed with water:

  • First, the mixture of spirit and water is put into a distillation flask
  • After that, the mixture of water and spirit is heated to a temperature of eighty degrees where the spirit will evaporate, while the water has not yet evaporated.
  • The spirit vapor is then cooled with a Liebieg cooler until it condenses and drips into the Erlenmeyer tube used to contain it.

In addition, in distillation there is a process that involves several components in chemical engineering, including:

  • Evaporation and condensation occur in the condenser and reboiler which results in two phases in equilibrium in the column.
  • Mass and heat transfer experienced by each stage, including the condenser or reboiler
  • Momentum transfer.
  • Phase balance, which occurs on the tray/plate where the vapor and liquid phases are in contact with each other.
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