Distillation is not only the most energy consumer but also the most frequently-adopted separation operation in chemical industries since it separates a mixture only by the difference among vapor pressures (boiling points) of components. So distillation is often called as the king of separation processes. Therefore, research and development of technologies on energy savings of distillation is an...

Batch and continuous systems are of multivariable in nature. A multivariable system is one in which one input not only affects its own outputs but also one or more other outputs in the plant. Multivariable processes are difficult to control due to the presence of the interactions. Increase in complexity and interactions between inputs and outputs yield degraded process behavior. Such processes ...

Simple distillation columns with ideal vapor-liquid equilibrium may display multiple steady-state solutions. Two fundamentally different sources for the multiplicity are presented. Both bring about the unexpected result that increasing reflux makes separation worse in the top part of the column. It corresponds to an unstable operating point. The first type of multiplicity is found for columns w...

The heat-integrated distillation column to be addressed in this paper is a special distillation column that involves internal heat integration between the whole rectifying and the whole stripping sections. An overview of the research on this process is presented in this work. It covers from the thermodynamic development and evaluations to the practical design and operation investigations for th...

A dynamic model for the simulation of the batch operation of a multicomponent packed distillation column is developed. The accuracy of simulation code is verified by using two types of mixtures (cyclohexane-n-heptane-toluene and ethanol–water) theoretically and experimentally. An optimum internal reflux ratio profile is searched to maximize the distillate amount of a specified concentration for...

Optimal control problems in batch distillation involve finding a trajectory for the reflux ratio so as to maximize a performance index. Then the controller is asked to follow this trajectory in an open loop fashion. It is important to minimize the effect of uncertainties in thermodynamic models on the optimal control profiles to achieve a better operating performance. The non-linear parameter e...