On the synthesis of multicomponent distillation configurations with nonsharp splits

In this paper, the nonsharp split and its effect to the synthesis of multicomponent distillation configurations are investigated. For any zeotropic mixture with N-component, two kinds of nonsharp splits can be introduced in a separation sequence, namely the symmetric nonsharp split which is fully sloppy split of the middle components, and the asymmetric split which is partially sloppy split of the middle components. First, with intended sharp and nonsharp splits, different distinct separation sequences can be formulated for a multicomponent distillation. For the distinct separation sequences, different ways to deal with the condensers and reboilers associated with submixtures of middle components are presented. It is shown that different traditional distillation configurations can be generated which may have equal to N-1 or more than N-1 columns. From the different traditional distillation configurations, the intensified distillation systems with less than or equal to N-1 columns are derived. It is shown that the combination of the individual columns in the traditional distillation configurations has dramatic effect to the generation of the intensified distillation systems. It is found that traditional distillation with more than N-1 columns gives more opportunities to synthesize the intensified distillation systems.