Heterogeneous azeotropic distillation in packed columns: Experimental results

Heterogeneous azeotropic distillation in packed columns is often very diffi cult because three phases, i.e., two liquid phases and one gas phase, can o ccur. In this type of distillation, also known as three-phase distillation, the second liquid phase can change the mass transfer efficiency of the pac king in a significant way. The present paper focuses on simple distillation experiments with the mixture acetone/water/toluene. The evaluation of thes e experiments helps us better understand the effects of a second liquid pha se on the mass transfer in a packed distillation column.