On the MINLP approach for optimal design of chemical engineering systems .2. Synthesis of distillation sequences

In this paper the MINLP method proposed in Part (I) is illustrated by applying it to; the synthesis problem of non-sharp distillation sequences. A MINLP formulation for the synthesis of distillation sequences with non-sharp separation is proposed. In this Formulation the recoveries of the key components are introduced as optimization variables and this makes it possible to synthesize a distillation sequence with specified component recoveries, and at the same time, renders the MINLP problem nonconvex. The solution procedure is illustrated with three example problems.