Effect of Water on Phenol Separation from Model Oil with Ionic Liquids Based on COSMO-RS Calculation and Experimental Study

Abstract

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–H2O 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 ([C2mim]­[Ac]) was selected as the representative IL, and then the molecular interactions between the [C2mim]­[Ac]–H2O 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 [C2mim]­[Ac]. The competition between them leads to decreasing separation performance for m-cresol of the [C2mim]­[Ac]–H2O 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 [C2mim]­[Ac] had a negative effect on the separation of m-cresol. The viscosity and UV–vis spectra of the [C2mim]­[Ac]–H2O 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.

Antibacterial performance enhancement using hydrophobic deep eutectic solvents: COSMO-RS prediction, experimental validation, and synergistic action with antibiotics

“…HDESs screening using COSMOthermX was performed. Three approaches are available, namely, electroneutral, metafile, and segmented or fragmented approaches, which are used to represent ILs in the COSMO software [26]; the electroneutral method is commonly used to screen ILs [27]. Because of the resemblance in their compositional structures, the electroneutral method was selected for the depiction of the DESs in COSMO-RS, namely HBA and HBD, as determined by their mole composition [28].…”

Screening of Double Solvents Based on Multi-Index Evaluation Method for the Selective Separation m-Cresol from Model Oil

“…Conductor-like screening model for real solvents (COSMO-RS) is a very useful method to screen extractants for mixture separation. , For IL screening, Lyu et al investigated the extraction capacity and separation selectivity at infinite dilution of 264 ILs to separate benzene and cyclohexane . Gao et al studied the capacity of 1860 ILs for thiophene (TS) and dibenzothiophene (DBT) .…”

Multiscale Screening of Deep Eutectic Solvents for Efficient Extraction of m-Cresol from Model Coal Tar

“…Compared with the abovementioned methods, the conductor-like screening model for real solvents (COSMO-RS) can calculate the thermodynamic properties of pure components and mixtures independent of the experimental data. − COSMO-RS showed relatively high accuracy in the qualitative and quantitative predictions of thermodynamic properties, which has been widely applied as an efficient DES screening model in different separation systems. − Nevertheless, the infinite dilution distribution coefficient and selectivity are chosen as screening indicators in the abovementioned works. These two indexes were incapable of investigating the effect of different feed compositions on the separation performance of DESs in a practical system .…”