Separating 2-Propanol and Water: A Comparative Study of Extractive Distillation, Salting-Out, and Extraction

Sander, Aleksandra; Rogošić, Marko; Frljak, Leonarda; Vasiljević, Daniela; Blažević, Iva; Parlov Vuković, Jelena (2025) Separating 2-Propanol and Water: A Comparative Study of Extractive Distillation, Salting-Out, and Extraction. Separations, 12 (8). ISSN 2297-8739

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Abstract

Separating azeotropes is an important, difficult, and expensive task, in particular for the 2-propanol–water mixture. The literature on the problem is rich in modeling studies but often lacking even the simplest experimental confirmation. In this paper, extractive distillation, liquid–liquid equilibrium-based extraction, and salting-out were experimentally tested for the desired separation. Among the four tested extractive distillation entrainers, none was able—in the investigated experimental setup—to push the system over the azeotropic composition threshold. Four novel hydrophobic deep eutectic extraction media were tested for the desired separation, and those based on menthol or thymol with decanoic acid were found most promising. Among 16 tested salting-out agents, 5 of them produced two-liquid phases, and only 4 hydrophilic inorganic salts promoted 2-propanol separation, with sodium carbonate being the most promising candidate. The purity of the products was tested with FTIR and 1H-NMR. The experimental findings were compared with COSMO-RS model predictions, with moderate success.

Item Type:	Article
Uncontrolled Keywords:	2-propanol–water azeotrope; extractive distillation; liquid extraction; salting-out; deep eutectic solvents; COSMO-RS
Subjects:	TECHNICAL SCIENCES > Chemical Engineering > Mechanical, Thermal and Separation Processes
Divisions:	NMR Center
Depositing User:	Lorena Palameta
Date Deposited:	29 Jul 2025 08:44
URI:	http://fulir.irb.hr/id/eprint/9919
DOI:	10.3390/separations12080196

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