The separation of maximum azeotropes in a batch rectifier by extractive distillation was investigated by rigorous simulation. The influence of the most important parameters was studied. The results obtained under continuous feeding of the entrainer were compared with those obtained by the batch distillation, where the whole quantity of entrainer is added to the charge before the start of the distillation. The calculation results obtained for the mixture acetone-chloroform using benzene and toluene as entrainer showed the benefits of the continuous feeding of the separating agent.