Our former method for the assessment of the feasibility of batch extractive distillation (usually performed in a rectifier with a heavy entrainer) was extended to the case where a light entrainer is fed continuously into a rectifier or a stripper. The method is based on the calculation of the vessel path and possible composition profiles of the column sections. The method is demonstrated for both configurations on the examples of separation of minimum boiling point azeotropic mixtures. For the rectifier the most important conclusions were also experimentally verified.