Key Words:PRESSURE-SWING DISTILLATION; PROCESS DESIGN; ACETIC-ACID; INTEGRATION; GLYCEROL

Abstract:The effective separation of the ternary azeotrope benzene/isopropanol/water has high economic benefits in industry. It is of great significance to study the dynamic controllability of this ternary azeotropic system. In this paper, dynamic control schemes of the conventional extractive distillation (CED) and the dividing wall extractive distillation (DWED) for benzene / isopropanol / water separation with ethylene glycol (EG) as extractant were studied. The open loop steady-state gain analysis is used to guide the control structure improvement, a multi-point temperature control strategy based on the sensitive stage temperatures is proposed to improve the control scheme. In the CED process, the improved control scheme can resist </n>20% feed flow and composition disturbances. In addition, it is demonstrated that using the steam separation ratio (bV) to control the sensitive stage temperature shows better dynamic performance compared with using the ratio of the steam side flowrate and the reboiler heat duty (V/R) to control the sensitive stage temperature in the DWED process. Finally, by comparing the integral of squared error (ISE) values, it is found that improved control schemes (CS2 and CS4) have better robustness and dynamic performance. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Volume:128

Issue:0

Translation or Not:no