Separation of Azeotropic Mixture (Water-Ethanol) Using Ionic Liquid

Azeotrope mixture is a liquid mixture which has constant boiling point and at a given pressure and temperature the liquid composition and vapor composition is the same where it is the equilibrium point. It has two or more component mixed together to form ‘inseparable” compositions. In my project, I took ethanol and water to represent the azeotropic mixture which will be formed at 96% volume of ethanol and 4% volume of water. With the existences of azeotropic mixture it will complicated the operating region of vapor liquid envelope of the equilibrium temperature.

There are four main objectives of this project which are:
• To find a replacement for benzene or toluene as an entrainer.
• To investigate the possibilities of using ionic liquid to separate azeotropic mixture (ethanol and water).
• To evaluate the performances of using ionic liquid to separate azeotropic mixture (ethanol and water).
• To compare the results of using different ionic liquid to separate azeotropic mixture (ethanol and water).

The scope of study for this separation process of ethanol and water using ionic liquid is conducted by performing experimental analysis purity of the separation. This is done by collecting, analyzing and documenting data obtained from simple distillation. For my project I will be using the simple distillation method to separate water and ethanol mixture. With that, I will be using three different types of ionic liquids to compare the performances of separating the water and ethanol mixture. So at first, simple distillation will be performed only for water and ethanol mixture followed by addition of benzene and toluene and also the three different ionic liquids.

The results are plotted and it will be discussed according to the works that have been done. Using three different types of ionic liquids will give the comparison which ionic liquid will be the best choice to separate water and ethanol mixture. Just to give an overview, 2-hydroxyethylammonium Lactate gives the highest value of ethanol been distillate out. Following are the graphs that are plotted:
i). Purity vs. volume of ionic liquid.
ii). Volume of ethanol distillate vs. volume of ionic liquid

By adding three different types of ionic liquids, water-ethanol mixture can break the azeotrope but 2-hydroxyethylammonium Lactate gives the highest value of ethanol been distillate out. Therefore, it opens new possibilities as an entrainer for this ionic liquid.