Heat integration of azeotropic distillation using benzene and cyclohexane as entrainers and pressure swing distillation for separation of water–ethanol mixture

Distillation is considered the most common separation method in chemical industries. However, the simple distillation method is not suitable for all mixtures. For instance, a mixture in which two or more components form an azeotrope may not be fully separated through simple distillation. Water and ethanol cannot be separated by simple distillation due to an azeotrope point. This study investigated separation of the water and ethanol mixture by azeotropic distillation (AZ) and pressure swing distillation (PSD). Benzene and cyclohexane were used as entrainers in azeotropic distillation. azeotropic distillation and pressure swing distillation methods consume a high amount of energy like all common distillation columns, necessitating the need for energy optimization in order to be economical. The feed was preheated by the bottom product to reduce energy consumption. The processes were evaluated with and without heat integration. According to the results, azeotropic distillation by benzene as an entrainer and heat integration was the best process reducing energy consumption by ۸۷% relative to pressure swing distillation.

Keywords:

Azeotrope , Azeotropic distillation , Pressure swing distillation , heat integration ,