2‑Propanol Dehydration via Extractive Distillation Using a Renewable Glycerol–Choline Chloride Deep Eutectic Solvent: Vapor–Liquid Equilibrium

• Published in: Journal of chemical and engineering data 2017-02, Vol.62 (2), p.872-877
• Main Authors: Zhang, Lianzhong, Zhang, Zheng, Shen, Dongping, Lan, Mingyang
• Format: Article
• Language: English
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/acs.jced.6b00912

A renewable deep eutectic solvent, glycerol–choline chloride (molar ratio 2:1), was tested as an entrainer for dehydration of 2-propanol by extractive distillation. Isobaric vapor–liquid equilibrium data for the quaternary system water + 2-propanol + glycerol + choline chloride were measured at 100 kPa. With the addition of the deep eutectic solvent, the azeotrope of water + 2-propanol can be removed at a solvent mass fraction of 0.142, which is much smaller than the minimum solvent mass fraction of 0.229 for glycerol alone. With regard to the relatively low viscosity as compared with glycerol, the deep eutectic solvent may have better performance when used as entrainer for 2-propanol dehydration. The NRTL equation was used for the modeling of the quaternary vapor–liquid equilibrium data. Binary parameters of water + 2-propanol, water + glycerol, and 2-propanol + glycerol were fixed as the same for the system water + 2-propanol + glycerol and were taken from the literature. The correlation appeared to be in good agreement with the experimental results. Mean absolute deviations were 0.15 K for equilibrium temperature and 0.0035 for 2-propanol mole fraction in the vapor phase, respectively.