Separation of Azeotropic Mixtures in Closed Batch Distillation Arrangements

Batch time (energy) requirements are provided for the separation of ternary zeotropic and heteroazeotropic mixtures in three closed batch column configurations. Two multivessel column modifications (with and without vapor bypass) and a conventional batch column operated under the cyclic policy, were studied. The multivessel column performs always better than the conventional column and the time savings vary from 24% up to 54 %. Moreover, by eliminating the vapor bypass in the multivessel, additional time savings of 26% can be achieved for a zeotropic mixture. However, the multivessel with the vapor bypass should be used for the heteroazeotropic mixtures.