Open AccessEffect of Water on Phenol Separation from Model Oil with Ionic Liquids Based on COSMO-RS Calculation and Experimental Study
Author(s) -
Qian Liu,
Jing Jing Bi,
Xianglan Zhang
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c04247
Subject(s) - chemistry , cosmo rs , cumene , cresol , phenol , dodecane , ionic liquid , selectivity , partition coefficient , dilution , hydrogen bond , organic chemistry , thermodynamics , molecule , catalysis , physics
Ionic liquids (ILs) are widely used in the extraction of phenolic compounds from low-temperature coal tar (LTCT). However, both ILs and LTCT contain a certain amount of water. The existence of water may have a remarkable impact on the phenol separation performance of ILs with different structures. In this work, the capacity and selectivity for m -cresol, as well as the solubility of cumene and dodecane in different IL-H 2 O mixtures, were firstly calculated by the conductor-like screening model for real solvents (COSMO-RS) at infinite dilution. The calculation covers ILs with different anionic and anionic structures and different water contents. To explore the effect of water in IL on separation performance, 1-ethyl-3-methyl imidazolium acetate ([C 2 mim][Ac]) was selected as the representative IL, and then the molecular interactions between the [C 2 mim][Ac]-H 2 O mixture solvent and solute (including m -cresol, cumene, and dodecane) were analyzed by COSMO-RS. The results indicated that both water and m -cresol could form hydrogen bonds with [C 2 mim][Ac]. The competition between them leads to decreasing separation performance for m -cresol of the [C 2 mim][Ac]-H 2 O mixture with increasing water content. Moreover, through analyses of m -cresol extraction efficiency, distribution coefficient, selectivity, and entrainment of cumene and dodecane, the experimental results confirmed that the presence of water in [C 2 mim][Ac] had a negative effect on the separation of m -cresol. The viscosity and UV-vis spectra of the [C 2 mim][Ac]-H 2 O mixture were also measured. Water in ILs should be removed as much as possible to ensure a better dephenolization effect and avoid phenol containing wastewater.