BATCH DISTILLATION IN A COLUMN WITH A MIDDLE VESSEL

This paper examines a new type of a batch distillation column which is built up from two separation sections and a vessel in between. Mixtures with constant relative volatilities are investigated. One of the most important features of the new column is that it has additional steady states on binary edges of the simplex which do not correspond to pure components. These steady states are saddle and unstable singular points of a dynamic system describing the process. Existence of additional steady states, their dependence on parameters and the introduction of one more parameter q add more flexibility to the process and provide new opportunities for batch distillation. For example, a binary mixture can be separated into pure components under finite reboil and reflux ratio.