Thermodynamic insights on batch and continuous extractive distillation

The extractive distillation of minimum and maximum boiling azeotropic mixtures A-B with a heavy or a light entrainer was introduced, intending to assess its feasibility based on thermodynamic insights. Differential equations are derived for each section composition, depending on operating parameters: distillate product purity and recovery, reflux ratio R and entrainer ¿ feed flow rate ratio FE/F for the heavy case; bottom product purity and recovery, reboil ratio S and entrainer ¿ feed flow rate ratio for the light entrainer case. This feasibility analysis methodology can be exploited to evaluate the feasibility under finite reflux ratio and both for batch and continuous operation.