Distillation is the process in which two or more compounds are separated based on their boiling points. The compound with a lower boiling point vaporizes first allowing it to be separated from the compound having a higher boiling point.
What is distillation?
During distillation, the mixture is placed in a container, and the two components of the mixture get separated into different containers. The condensed vapor is called the condensate or distillate.
What is simple distillation?
Simple distillation involves a single vaporization/condensation cycle. Simple distillation is used to separate compounds with widely differing boiling points where both compounds want to be collected.Â
It can also be used to purify a liquid that contain either non-volatile impurities such as salt or very small amount of another liquid with a significant difference in boiling points from the liquid to be purified. If two liquids have a boiling point difference of more than 40-50 C, simple distillation will not be effective at separating them. In this case fractional distillation is a must.
What is fractional distillation?
Fractional distillation is like a series of simple distillations. However, instead of having multiple pots and condensers, the vaporization/condensation cycle occurs in a single distillation column.Â
In fractional distillation, vapor rises up the column and condenses. It them re-evaporates, rises up the column and condenses again. With each cycle the vapor becomes enriched in the component with the lower boiling point. In this way, fractional distillation accomplishes in one apparatus what would require several simple distillation setups.
In fractional distillation, fractionating columns are insulated in order to allow multiple vaporization/condensation cycles to occur within a single column. The most volatile component vaporizes first. The vapor then condenses on multiple surfaces in the fractionating column, and the resulting liquid vaporizes again.Â
During each step, the vapor becomes more enriched in the more volatile component with the lower boiling point. In this way fractional distillation accomplishes in one apparatus what would have required multiple simple distillation steps.
You can read more about the procedure of fractional distillation here:Â Procedure of Fractional Distillation.
Advantages and Disadvantages of Fractional Distillation
Advantages of Fractional Distillation
- It requires the least amount of items in the apparatus to perform fractional distillation.
- The apparatus has a fractionating column which makes separating the two components of a mixture easy.
- It is highly efficient to perform fractional distillation when separating two components of a mixture.
- The process of fractional distillation foes not require high boiling point difference between the components of the mixture.
- Fractional distillation gives better separation of components when compared to other forms of distillation.
1. It requires the least amount of items in the apparatus to perform fractional distillation.
The list of apparatuses that are required for the process of fractional distillation are:
- Condenser
- Distilling flask
- Fractionating column
- Thermometer
- Heat source such as a Bunsen burner
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2. The apparatus has a fractionating column which makes separating the two
components of a mixture easy.
Advantages of Fractionating column
- They help to separate mixture by allowing the mixed vapors to cool, and be be collected later.
- They can help separate compounds that have relative close boiling points.
- They can also separate compounds based on their property of adsorption, absorption, size etc.
- The more the number of channels better is the separation. Type of packing material also influences this.
3. It is highly efficient to perform fractional distillation when separating two components of a mixture.
Is fractional distillation more efficient than simple?
Yes, fractional distillation is more efficient that simple. It is so because fractional distillation gives a distillate which is purer than the distillate formed by using simple distillation.
4. The process of fractional distillation does not require high boiling point difference between the components of the mixture.
5. Fractional distillation gives better separation of components when compared to other forms of distillation.
Disadvantages of Fractional Distillation
- Fractional distillation cannot separate solute and solvent. The mixture needs to be a liquid-liquid solution to be distilled by fractional distillation.
- It requires complex and expensive distillation columns and reflux for industrial fractional distillation.
- It takes a lot of time to perform fractional distillation.
- The process needs to be done multiple times.
- Operational risks are involved in conduct fractional distillation.
1. Fractional Distillation cannot separate solute and solvent. The mixture needs be a liquid-liquid solution to be distilled by fractional distillation.
To perform fractional distillation, one cannot choose a mixture which is made up of a solute which is dissolved in a solvent. This is because the apparatus is meant to separate only two liquid mixtures. It is unable to separate a solid particles. The apparatus just isn't made for that.
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