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Heterogeneous extractive batch distillation of the chloroform -methanol minimum boiling temperature azeotropic mixture is studied with water as a heterogeneous entrainer. The continuous feeding of water allows recovering 99%molar chloroform after condensation of the saddle binary heteroazeotrope waterchloroform. Unlike a homogeneous process, the reflux composition is different from the heteroazeotrope water -chloroform in the vapor overhead. Besides, the distillate recovery is improved by refluxing a portion α of the chloroform-rich distillate phase along with the water-rich entrainer phase. A genetic algorithm is coupled to a constant molar overflow model to study seven operation policies. Optimization parameters are the entrainer flowrate F E /V, the portion α T3 of distillate-rich phase refluxed to the column during chloroform distillation, the reflux policy R T5 during methanol distillation. The optimization maximizes a profit function, penalized with recovery yields constraints whereas purity targets are used as Task ending events. All optimized solutions achieve higher than 90%molar recovery yields and 99%molar purity for both products chloroform and methanol. Results are confirmed by rigorous simulation showing the good performance of coupling simplified model and genetic algorithm as a first approach. The two piece-wise parameter values operation policies for all three parameters increases profit by 41.8% and reduces total time by 43.8% compared to single value parameter policy. The parameter influence study ranks R T5 first, α T3 second and F E /V last. Keeping F E /V constant and using two piece-wise α T3 and R T5 value operation is recommended to increase profit.

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OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://oatao.univ-toulouse.fr/ Eprints ID: 4157Any correspondence concerning this service should be sent to the repository Abstract This paper considers the optimisation of batch extractive distillation, using heterogeneous entrainers for the first time. The objective function includes the maximum of overall profit and the optimisation variables are the entrainer flowrate and the reflux ratio that is an optimal combination of both decanted phases. Simulation and optimization is performed within MATLAB, by using a genetic algorithm coupled to a short-cut model of the distillation column. The performance of the optimisation scheme is illustrated through the separation of chloroform -methanol mixture with water considering either a constant or a piecewise constant policy for both optimization variables.