Modeling, Simulation and Control of Middle Vessel Batch Distillation Column

Batch distillation is a very efficient unit operation which allows the fractionation of a multicomponent mixture into its pure constituents in a single column. Due to its flexibility and low capital costs, batch distillation is becoming increasingly important in the fine chemicals and pharmaceutical industries. However, the regular batch distillation processes have some disadvantages, such as high energy demands and high temperatures in the feed vessel. An alternative to the regular batch distillation is the middle vessel batch distillation. With this type of process it is possible to obtain simultaneously light and heavy boiling fractions from the top and the bottom of the column respectively and intermediate boiling fraction accumulates in the middle vessel. This work dealing with the modeling and simulation of middle vessel batch distillation column (MVBDC) neglecting the vapor hold and its influence on the process. Modeling of MVBDC is done based on the combined first principle model and empirical relations. The startup of MVBDC is covered. Here we also deal with the control of distillate composition and condenser hold up and process gain estimation. Predominantly theoretical studies regarding controlled variables are studied. (c) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Noorul Islam Centre for Higher Education