Energy-Saving Mechanism in Heat Transfer Optimization of Dividing Wall Column

Currently most of the dividing wall column (DWC) designs are based on a Petlyuk Column in which the heat transfer process across the dividing wall is ignored. This paper proposes a heat transfer model of DWC, in which additional virtual intermediate heat exchangers are introduced between the prefractionator and the main column, and thus the heat transfer process among the virtual intermediate heat exchangers will produce the thermal-coupled effect. This effect can be explored by fixing the beneficial heat transfer region and a corresponding algorithm of heat transfer. Compared with the designs based on a Petlyuk Column, this DWC model can further reduce the exergy loss and energy consumption. Besides, the optimal operating zone is enlarged, and the influence of liquid and vapor split ratio fluctuation on the minimum energy consumption of DWC is lowered. This model provides a guidance for the energy-saving design of DWC.