Vapor recompression with interreboiler in a ternary dividing wall column: Improving energy efficiency and savings, and economic performance

This work deals with a ternary dividing wall column (DWC) for improving its energetic and economic potential through thermal intensification route. In this light, a vapor recompression heat pump system in conjunction with an interreboiler (IR) is proposed to configure externally with the classical DWC scheme that allows heat transfer through the dividing wall. Formulating a variable manipulation policy at dynamic state, it is investigated that the vapor recompressed DWC with inter and bottom reboiler (VRDWCIBR) shows a better performance than the VRDWC with either bottom reboiler or interreboiler(s). For a ternary hydrocarbon system, the VRDWCIBR secures the best performance, providing a 81.05% savings in utility consumption (which is double to that of DWC) with a thermodynamic efficiency of 55.60% and a payback time of 2.82 years. The proposed heat integration arrangement can be retrofitted with a little modification in the classical DWC column.