1. Choice of process depending on the type of mixture to be separated

Distillative separation of non-ideal, azeotropic or low-relative-volatility mixtures is more complex in both operation and design than conventional distillation. Figure 1 shows the various processes that can be used to separate a zeotropic, azeotropic or low-relative-volatility binary A-B mixture (criterion α _AB < 1.5, see [J 2 611] ):

• a – classical distillation for ideal mixtures (see the file Material transfer: ideal compartmentalized distillation