Improving energy efficiency and cost-effectiveness of batch distillation for separating wide boiling constituents. II: Internal versus external heat integration

In the first paper of this series, we developed a vapor recompressed batch distillation (VRBD) scheme by means of external heat integration. This contribution aims at devising an internally heat integrated batch distillation with a concentric reboiler (IHIBDCR) configuration, in which the rectifying tower is surrounded by a jacket. The operating cost can be reduced with the improvement of energy savings substantially through seeking further external heat integration under the framework of vapor recompression mechanism in the IHIBDCR structure between the overhead vapor and the reboiling liquid. The features of both the IHIBDCR system and its hybrid form that combines the vapor recompression column (VRC) and the IHIBDCR scheme are illustrated by a binary mixture having wide boiling constituents, with special emphasis focused on the comparative performance study between the externally integrated VRBD presented in Part 1 of the current work, the internally integrated IHIBDCR arrangement and the hybrid structure.