Evaluation of a novel configuration of bottom flashing on dual distillation columns for saving energy

Vapor recompression and bottom flashing are among the developed technologies for enhancing energy efficiency of distillation processes. In this paper, a novel configuration of bottom flashing system is proposed for enhancing energy efficiency of dual columns such as direct distillation sequences. The system is designed to operate between two distillation columns. The proposed system engages two separate distillation columns, both of which can be wide boiling systems. The system incorporates two interacting bottom flashing systems that engage the two distillation columns through heat transfer from the top product of the second column to the bottom product of the first column which in turn results in elimination/reduction of utility requirements of condenser of the second column along with reboiler of the first column. Based on the results of this study, compared to conventional direct sequence distillation, 40.3% reduction in energy requirements and 20.7% reduction total annual costs of the process can be obtained through application of the proposed system.