Dynamic control of the pressure-swing distillation process for THF/ethanol/water separation with and without thermal integration

Abstract

When evaluating the distillation process, it is necessary to consider its economic performance and its controllability. In this study, a strategy was developed to realize the stable control of pressure swing distillation without thermal integration in the face of 20% flow and composition disturbances. Through an exploration of the heat integration between different distillation columns, three partial and one full thermal integration processes were developed. The robust control of these processes was realized by adding reboiler heat duty and feed ratio (Q/F) control structures. Finally, the three processes were compared in terms of control and economy, and it was found that the controllability of the full thermal integration process was slightly inferior to that of the pressure swing distillation without thermal integration. However, the full thermal integration process consumed 29.48% less energy compared to process without thermal integration and resisted ±20% flow and composition disturbances. This research has a certain reference and guiding significance for the process design and control strategy design of triple column swing pressure distillation in industry.