Chemical Engineering Research & Design, Vol.120, 138-149, 2017
Numerical simulation of dividing wall column with vapor recompression located at side product stage
The energy efficiency of dividing wall column (DWC) can be further improved by the vapor recompression (VRC), but large temperature difference between overhead and bottom of the DWC hindered their combination. Meanwhile, it is difficult to choose suitable side heat exchanger position in the DWC. In this paper, we provided a direct method to design the configurations that the VRC assisted DWC at the side product stage. The Column Grand Composite Curve (CGCC) profiles were used to determine the type of phase withdrawn from the side product stage. In the CGCC profiles, if the side product stage was located in the side reboiler region, the vapor should be withdrawn from the side product stage, the SCVRC-DWC and IR-SRVRC-DWC configurations can be achieved. If the side product stage was located in the side condenser region, the liquid should be withdrawn from the side product stage, the SRVRC-DWC and the IC-SRVRC-DWC configuration can be achieved. Three separation cases with different ESI values were simulated and the results inferred that the proposed configurations had high energy efficiency when enough vapor or liquid flow can be withdrawn from the side product stage. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.