Vapor-liquid equilibrium experiment and process simulation of extractive distillation for separating diisopropyl ether-isopropyl alcohol using ionic liquid

Publication date: 1 November 2019Source: Journal of Molecular Liquids, Volume 293Author(s): Jun Qi, Qingjun Zhang, Xiaoyan Han, Qingpeng Wu, Yafang Li, Qunsheng LiAbstractThe formation of azeotrope makes the separation of diisopropyl ether (DIPE) and isopropanol (IPA) a challenging task. Ethylene glycol (EG) and ionic liquid 1,3-dimethylimidazolium dimethyl phosphate ([Mmim] [DMP]) were screened as entrainers for the extractive distillation process. Isobaric vapor-liquid equilibrium data of DIPE + IPA + EG and DIPE + IPA + [Mmim] [DMP] was measured through experiment. The NRTL model was applied to correlate the experiment data and predict the effect of entrainers on the phase behavior of azeotrope in the full concentration range. The results indicate that [Mmim] [DMP] performs better ability than EG in enhancing the relative volatility of DIPE/IPA azeotrope and eliminating azeotropic point. The design and simulation of the two extractive distillation schemes were carried out after embedding the model parameters and the physical properties of IL into Aspen Plus. The optimal operating parameters were obtained though the sequential iterative procedure based on the total annual cost (TAC). The results of the economic analysis showed that the scheme 2 using the flash tank instead of the solvent recovery column has 24.582% reduction of TAC and 31.241% energy savings compared to the scheme 1.
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research