Comparison of heterogeneous azeotropic and pressure-swing distillations for separating the diisopropylether/isopropanol/water mixtures

摘要

Isopropanol and diisopropylether are the two important organic solvents in the chemical industry. The diisopropylether/isopropanol/water mixtures contain multiple homogenous and heterogeneous minimum-boiling azeotropes being sensitive to the pressure. In the present study, three separation alternatives, including a new heterogeneous azeotropic distillation (HAD) and two conventional pressure-swing distillations (PSD), are designed conceptually on the ternary diagram of this mixture. And then their optimal design parameters are obtained via the sequential iterative search procedure based on the minimum total annual cost. Furthermore, several partial or full heat integration schemes of the optimal configuration are constructed and explored by using the temperature-enthalpy diagram. The result shows that the most competitive heat-integrated PSD configuration compared to the HAD can save 19.47% and 16.14% in the energy consumption and TAC, respectively. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.