Differences Between Azeotropic And Extractive Distillation

Azeotropic vs Extractive Distillation

Azeotropic and extractive distillations are techniques used in the field of chemistry and engineering. Major industries, especially pharmaceuticals, are making use of these techniques to further improve their research. Distillation is a very important process in separating certain components from the mixture and is typically based on the volatility of the components in the mixture of the boiling liquid. Although these techniques are usually compared with each other, many chemical engineering students are still confused about the difference. Azeotropic and extractive distillations have some similarities but they also have distinct differences and these are observed on the processes. In chemistry, these processes are very essential in separating certain mixtures to form a new product. By comparing these two processes, you can see their differences.

What is azeotropic distillation?

Azeotropic distillation is a process of distillation wherein you can add certain components into the mixture to have a better separation process. Usually, the certain component added into the mixture is water or benzene, because these can help in increasing the volatility of a substance. By the way, volatility is the capacity of the substance to vaporize. In this process, the distillation process could form an azeotrope which can greatly help in the exact process of the separation because it won’t alter the components like a simple distillation would. Azeotropic distillation produces a heterogeneous mixture. In this method, an entrainer is used to trap particles in the current to separate the azeotrope.

What is extractive distillation?

Extractive distillation is a distillation technique wherein the capability of mixing or miscibility, the component of being non-volatile, and even a high boiling point, could be the measurement of separating a mixture without even forming an azeotrope. This kind of method is usually used for mixtures with almost the same volatility. In this method, a separation solvent will be used to interact with the mixture, thus helping the separation of the components. The good thing about this method is that by using the separation solvent, you can already easily separate the mixture without forming an azeotrope, which is common in other separation methods.

How do these two differ?

Azeotropic and extractive distillations are both methods of separating mixtures. Both of them also use a certain separating solvent to help in the process. The main difference between the two is in the process of separating the mixture. Azeotropic distillation forms an azeotrope right after combining the separation solvent. This azeotrope can be a complicated way of separating the mixture because it cannot be easily changed by just a simple distillation. In extractive distillation, a specific separation solvent is used in every mixture that should not form an azeotrope. In this way, extractive distillation is a better and easier method than the azeotropic distillation. But you need to bear in mind that if you have a mixture with very different volatilities, then the most effective separation method would be the azeotropic distillation.

Summary:

1. Azeotropic and extractive distillations are techniques used in the field of chemistry and engineering.

2. Azeotropic distillation is a process of distillation wherein you can add a certain component into the mixture to have a better separation process. Usually, the certain component added into the mixture is water or benzene, because these can help in increasing the volatility of a substance.

3. Extractive distillation is a distillation technique wherein the capability of mixing or miscibility, the component of being non-volatile, and even a high boiling point, could be the measurement of separating a mixture without even forming an azeotrope. This kind of method is usually used for mixtures with almost the same volatility.

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