Separation of azeotrope (2,2,3,3-tetrafluoro-1-propanol + water) via heterogeneous azeotropic distillation by energy-saving dividing-wall column: Process design and control strategies

To separate the azeotrope of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water, the energy-saving heterogeneous azeotropic dividing-wall column (DWC) is proposed using chloroform as an azeotropic agent. Compared with the conventional design, the total condenser duty reduction of 44.57%, total reboiler duty reduction of 42.66% and TAC reduction of 37.79% by the DWC design are obtained. Based on the simulation results, the energy-saving in the DWC design is due to the thermal coupling of the conventional design and the separation of water by the decanter with the purity of 99.5 mol%, rather not to the removal of remixing effect for the column sequence. The control strategy performance for the conventional and DWC designs are satisfactory, since TFP and water are separated with high purity, despite the disturbances of the flow rate of fresh feed, fresh feed composition and liquid split ratio.