Assessment of the implementation of vapor recompression technique in batch distillation

As the cost of energy continues to rise and the alarm bell on global warming has started ringing, it becomes imperative to reduce energy consumption by improving the thermodynamic efficiency of industrial processes. In this light, the direct vapor recompression column (VRC) has emerged as an attractive scheme by means of thermal intensification with great potential for energy saving. Although the external heat integration through VRC route has been proved to be an effective way for the enhancement of thermal efficiency of continuous distillation columns, the research on vapor recompressed batch distillation (VRBD) has just started. In this novel thermally integrated VRBD system, either the vapor inflow rate to the compressor or the external heat input to the reboiler is manipulated throughout the unsteady state batch operation. In order to broaden its applications, in this contribution, we aim at exploring the energetic and economic potentials of VRBD structure for the separation of a nonreactive binary system in addition to a complex reactive multicomponent mixture. Simulation results show the superiority of the VRBD column over the conventional standalone column in both the cases.

► A vapor recompressed batch distillation (VRBD) is devised.
► It manipulates either the vapor inflow rate to the compressor or the external heat input to the still.
► The features of VRBD are illustrated with two example systems.
► Simulation results show the superiority of the VRBD column over its conventional counterpart.