Screening ionic liquids solvent for separation of oil and hydroxybenzene mixtures based on COSMO-RS model

LIU Qian1 ZHANG Xianglan1 LI Wei2

(1.School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing) , Beijing, China 100083)
(2.School of Chemical Engineering, Beijing Institute of Petro-chemical Technology, Beijing, China 102600)

【Abstract】Phenolic compound separation of low temperature coal tar (LTCT) is important for its effective utilization. Based on the COSMO-RS model, with m-cresol and cumene as model compounds, ionic liquids were used as extractants for the separation of the oil and phenol system. A σ-profile database including 27 anions and 48 cations were established by Turbomole, screening the 1 296 ionic liquids by COSMOtherm. The influences of cations and anions on the separation of the m-cresol and cumene were investigated and some of them were verified by liquid-liquid equilibrium (LLE) data of ternary system, which indicated that the selection method of ionic liquid solvents was effective. The results show that the influences of the anions on the separation are more than those of the cations. Some ionic liquids are effective on separation, which contain Clor CH3COOin anions, because of the stronger hydrogen bond interaction between these ionic liquids and m-cresol. The increase of length of alkyl chain and the number of side chains can improve the separation effect of ionic liquid to m-cresol. The LLE data of ternary system of bmimOAc–m-cresol–cumene, bmimCl–m-cresol–cumene, emimOAc–m-cresol–cumene and TPAC–m-cresol–cumene by experiment show that the four kinds of ionic liquids have greater distribution coefficient and selectivity for m-cresol, and the order of extraction and separation effect was: emimOAc > bmimOAc > TPAC > bmimCl, which is consistent with the results obtained by COSMO-RS simulation screening, indicating that the screening has high accuracy.

【Keywords】 ionic liquids; phenolic compounds; COSMO-RS model; activity coefficient; separation; liquid-liquid equilibrium;


【Funds】 National Key Research and (2016YFB0600305)

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(Translated by REN XF)


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This Article


CN: 11-1946/TQ

Vol 69, No. 12, Pages 5100-5111

December 2018


Article Outline


  • Introduction
  • 1 Screening of ionic liquids
  • 2 Experimental materials and methods
  • 3 Results and discussion
  • 4 Conclusions
  • Symbol description
  • Appendix 1
  • Appendix 2
  • References