Process design, evaluation and control for separation of 2,2,3,3‐tetrafluoro‐1‐propanol and water by extractive distillation using ionic liquid 1‐ethyl‐3‐methylimidazolium acetate

Abstract

AbstractBACKGROUND2,2,3,3‐tetrafluoro‐1‐propanol (TFP) is a good solvent that is applied in the electronic industry. To recover TFP from its aqueous solution, conventional distillation cannot be adopted because TFP and water can form a minimum azeotrope.RESULTSIn this work, extractive distillation is applied to separate the azeotropic mixture of TFP and water using 1‐ethyl‐3‐methylimidazolium acetate ([EMIM][Ac]) as an entrainer. Based on the analysis of residual curve map, three processes are designed to separate the mixture. Extractive distillation processes (EDP) I and II consist of an extractive column and two flashes, and EDP III consists of an extractive column, a flash, and a stripper. For evaluating the three processes, total annual cost (TAC), CO2 emissions and global energy consumption (GEC) are considered into the objective function.CONCLUSIONThe simulated results show that EDP III with an extractive column, a flash, and a stripper can provide better economic and environmental benefits. Water can be obtained from the extractive column with a molar purity of 99.7%. TFP can be separated from the top of the flash and stripper with a molar purity of 99.7%. Furthermore, the control structure with two‐point temperature for EDP III is explored and it shows good responses for the disturbances of feed flow rate and composition.