Comparison of pressure-swing distillation and heterogeneous azeotropic distillation for recovering benzene and isopropanol from wastewater

Abstract Two methods of pressure-swing distillation (PSD) and heterogeneous azeotropic distillation (HAD) are investigated to recover benzene and isopropanol from wastewater. This ternary mixture can form two homogenous azeotropes (binary) and two heterogeneous azeotropes (binary and ternary), which all are sensitive to pressure. The proposed configurations are rigorously simulated and optimized based on the minimum total annual cost (TAC) via the sequential iterative procedure, and meanwhile the partial heat integration is taken into account respectively. The results show that both configurations of PSD are superior to the HAD configuration combining with PSD from the perspectives of economic and energy.