A novel combination of internal and external heat integrations in batch distillation: Application to a reactive system

Abstract

Studies on the thermal integration of batch rectifier have received almost no attention, although it is well-known for continuous distillation since the 1960s. In this contribution, we aim to develop an energy integration approach for batch distillation columns by thermally coupling the rectification tower with the concentric reboiler that surrounds the tower as a jackted. In this internally heat integrated batch distillation with a jacketed reboiler (IHIBDJR), the vapor produced in the concentric reboiler is compressed and then it enters the bottom of the rectifier. With the judicious use of internal heat source, the proposed IHIBDJR shows its attractiveness in terms of energy savings and payback time of excess capital. The pressure elevation from the jacketed reboiler to rectifying section generates a possibility of further intensification through the introduction of direct vapor recompression mechanism in the IHIBDJR. This novel combination of internal and external heat integrations can utilize the latent heat, an additional internal source, released by the compressed overhead vapor in vaporizing the reboiler liquid. After deriving the general form of this combined heat integrated structure, the mechanism is finally illustrated by a batch reactive distillation. This hybrid configuration shows promising energetic and economic potential over the IHIBDJR and its conventional counterpart.