Separation of Acetonitrile + Water Azeotropic Mixture using Deep Eutectic Solvent as Entrainer by Extractive Distillation

Abstract

Acetonitrile is an organic solvent which shows significant chemical and physical properties in the field of organic synthesis, pharmaceuticals, liquid chromatography. And also as a photosensitive material and extracting solvents. As it is a known toxic chemical, its ejection to water bodies is a serious threat, so there is a need of purification of acetonitrile from water because of its high importance. Earlier, in industries, conventional and ionic solvents has been used for the separation but due to non-eco-friendly nature they had face some drawbacks. So researchers evolve green solvents which can reduce the solvent related damage green. Deep eutectic solvents (DESs) are now regarded as new emerging green solvents which are widely in use. In this study, DES of ethylene glycol and choline chloride (EC) in ratio (2:1) acts as entrainer that separates the azeotropic blend of acetonitrile + water. A modified Othmer recirculation still was taken for quantifying the VLE data. For pseudo binary system DES EC(2:1) + water , DES EC(2:1) + ACN at room temperature the VLE data was calculated and for pseudo ternary system DES EC(2:1) + ACN + water the VLE data was computed at different DES mol % and these are- 5%, 10%, 12%. From this study, it has been found that EC (2:1) is a remarkable component that separates the ACN + water azeotropic blend. After this, a non-random NRTL model was used for thermodynamic modeling. Then, a fine confirmation of the experimental data and the forecast values for this system was found. In the result, it has been found that the used DES acts as a good entrainer for the separation ACN + water azeotrope.