@article{ZHANG2025, 
author = {YingYing ZHANG and LongHuan WU and XuZhao YANG and RunYi LIU and DaMing WU and Ying LI and RuiXue ZHANG and ZiHan FENG},
title = {Extraction and separation of benzene/n-hexane using a deep eutectic solvent consisting of a dicationic ionic liquid and a polyol},
year = {2025},
journal = {Journal of Beijing University of Chemical Technology (Natural Science Edition)},
volume = {52},
number = {4},
pages = {10-19},
keywords = {dicationic ionic liquid, deep eutectic solvents, extraction, benzene, n-hexane},
url = {https://www.sciopen.com/article/10.13543/j.bhxbzr.2025.04.002},
doi = {10.13543/j.bhxbzr.2025.04.002},
abstract = {The boiling points of benzene and n-hexane are similar, and they readily form an azeotropic mixture. Current separation processes have high energy consumption and low separation efficiency. In order to efficiently separate the benzene/n-hexane system, an asymmetric dicationic ionic liquid 1-(3-(trimethylammonium)propan-1-yl)-3-methylpiperidine dibromide ([N111C3MPi]Br2) (a hydrogen bond acceptor) was synthesized. [N111C3MPi]Br2 was subsequently mixed with ethylene glycol (a hydrogen bond donor) in different proportions to prepare a deep eutectic solvent [N111C3MPi]Br2/ethylene glycol. The density and viscosity of the deep eutectic solvent were measured in the temperature range 288.15-323.15 K. The results show that the density of the deep eutectic solvent decreased linearly with increasing temperature, and the viscosity decreased gradually. At 313.15 K, the viscosity of [N111C3MPi]Br2/ethylene glycol (molar ratio of 1∶6) was only 25.57 mPa·s. Using the deep eutectic solvent as the extractant, the conditions for separation of benzene/n-hexane were optimized by orthogonal tests, namely a separation time of 1.5 h, separation temperature of 313.15 K, feed ratio (volume ratio of deep eutectic solvent to benzene/n-hexane solution) of 1∶1. Under the optimized conditions, the distribution coefficient and selectivity of benzene were 9.29 and 120.83, respectively, which were significantly higher than those reported using sulfolane and other ionic liquid systems.}
}