Heterogeneous entrainer selection for the separation of azeotropic and close boiling temperature mixtures by heterogeneous batch distillation

The presence of azeotropes in multicomponent mixtures complicates the desig n of batch distillation separation processes widely used in pharmaceutical and speciality chemical industries. Most of those processes include the use of homogeneous, entrainer to ease the separation. We describe novel method s to break azeotropes using an entrainer that is partially miscible with on e of the initial binary mixture components. The core of the paper presents the rules for the selection of a heterogeneous entrainer leading to a feasi ble proc. ess for the Separation of a minimum or maximum temperature azeotr opic binary mixture or a close boiling binary mixture. Through several illu strating examples, we depict some of the advantages of heterogeneous batch distillation processes: more design alternatives for the separation of an a zeotropic binary mixture than with homogeneous batch distillation, simplifi ed distillation sequences as a consequence of fewer distillation tasks, cro ssing of batch distillation boundaries due to the reflux of either one or b oth of the decanter phases.