Pressure swing batch distillation by double column systems in closed mode

Two new double column systems operated in closed mode are suggested for pressure swing batch distillation. These configurations are investigated by feasibility studies based on several simplifying assumptions (e.g., infinite plate number, no stage hold-up) and are compared with double column batch rectifier and double column batch stripper in open mode. We study the configurations also by rigorous simulation based on less simplifying assumptions using a professional dynamic simulator. For the different configurations the influence of the most important operational parameters is studied. The results obtained for open and close modes are compared. The calculations and the simulations are performed for a binary minimum (acetone–n-pentane) and for a maximum (ethylene-diamine–water) azeotrope mixture.