**7. Conclusions**

In this study, the mass transfer efficiency of the extractive distillation with ionic liquids has been analyzed for the water ethanol mixtures using a developed rate-based model and in a pilot plant scale extractive distillation column.

The results from the rate-based indicated that the use of ionic liquids as solvents in ED is beneficial due to the increase in relative volatilities when compared to organic solvents.

The high viscosities of ionic liquids were reflected in the increase of que liquid phase viscosity inside the ED column. However, this viscosity did not decrease the mass transfer efficiency of the ED whereas the relative volatilities are high. On the other hand, when very high viscosities or high solvent to feed ratios are applied to the ED column, a decrease in mass transfer efficiency was observed even though having high relative volatilities.
