281868 Comparison of Extractive Distillation and Pressure-Swing Distillation for Methanol-Chloroform System

Wednesday, October 31, 2012: 10:30 AM
323 (Convention Center )
Eda Hosgor and Devrim B. Kaymak, Department of Chemical Engineering, Istanbul Technical University, Istanbul, Turkey

Two of the most common methods for separating a binary homogeneous azeotrope are extractive distillation and pressure-swing distilllation. The first method is effective if a suitable entrainer can be found, while the second one is effective if the composition of the azeotrope changes significantly with pressure. In this study, the steady-state designs of these methods will be developed for a methanol-chloroform binary system which is an effective solvent for extraction of bioactive substances from biological sources. For this binary system extractive distillation is feasible using water as the entrainer. Also the pressure-swing distillation is feasible since the minimum-boiling azeotrope at 1 atm contains 63,32 mol % chloroform at 327 K and at 10 atm the azeotropic composition is 40,83 mol % chloroform at 404 K. For all the process simulations the feed mixture contains 50 mol % chloroform 50 mol % methanol with a flowrate of 100 kmol/h and the purities of the two products are set at 99.5 mol %. Wilson model is used as thermodynamic model. For the extractive distillation process, the design variables to be optimized are; entrainer flowrate, extractive distillation total number of stages, fresh feed and entrainer feed locations, entrainer recovery column total number of stages, feed location of entrainer recovery column. For the pressure swing distillation process, the design variables to be optimized are; total number of stages and feed locations for both columns and recycle flowrate. The aim of this study is the comparison of steady-state designs of these methods by investigating the effects of design variables and total annual costs.

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See more of this Session: Process Design I
See more of this Group/Topical: Computing and Systems Technology Division