Work

Isopropanol dehydration by batch extractive distillation under variable pressure

Year: 2025

Type: article

Abstract: The recovery of isopropanol (IPA) in high purity in an industrial column from nearly azeotropic IPA(A)-water(B) mixture by batch extractive distillation is studied by dynamic simulation and optimization. The solvent DMSO (S) is much heavier than A and B. When the temperature of the heating steam is limited, the high boiling point of S (T BP,S ) may require the application of a lower pressure (e.g. vacuum) than that of A/B separation. Three different pressure policies are studied and compared: operation at atmospheric pressure, in vacuum and at progressively reduced pressure. The profit of one batch is maximized with the Box-complex method. The optimization parameters are the feed plate of S, purity and flow rate of S, reflux ratios and stopping criteria of several steps. The volume of the liquid in the reboiler and the purity of the IPA and that of wastewater sent to biological purification mean constraints for the optimization. The CO 2 emissions of the different policies are also compared. The profit obtained in vacuum was higher by 1.03 % than at progressively reduced pressure and by 6 % than at atmospheric pressure. However, the CO 2 emission was the lowest when the pressure was progressively reduced.

Source: Separation and Purification Technology

DOI: 10.1016/j.seppur.2025.133178

Authors: Laszlo Hegely, Bence Nemeth, Peter Lang

Institution: Budapest University of Technology and Economics

Language: English

Topic: Process Optimization and Integration

Subfield: Control and Systems Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $4,060