COLLOCATION METHODS FOR DISTILLATION DESIGN .2. APPLICATIONS FOR DISTILLATION

We present applications for a collocation method for modeling distilla tion columns that we developed in a companion paper. We discuss implem entation of the model, including discussion of the ASCEND system, whic h enables us to create complex models with simple building blocks and interactively learn to solve them. We first investigate applying the m odel to compute minimum reflux for a given separation task, exactly so lving nonsharp and approximately solving sharp split minimum reflux pr oblems. We next illustrate the use of the collocation model to optimiz e the design a single column capable of carrying out a prescribed set of separation tasks. The optimization picks the best column diameter a nd total number of trays. It also picks the feed tray for each of the prescribed separations.