Effect of different co-solvents on solubility of ILs [Emim]Ac, [Bmim][NTf2] in scCO2

• Published in: Journal of molecular liquids 2019-06, Vol.284, p.102-109
• Main Authors: Li, Gen, Zhou, Dan, Xu, Qin-Qin, Qiao, Guo-Yue, Yin, Jian-Zhong
• Format: Article
• Language: English
• Subjects: Co-solvent; Correlation; ILs; scCO2; Solubility
• ISSN: 0167-7322
• DOI: 10.1016/j.molliq.2019.03.174

Solubility of ILs [Bmim][NTf2] and [Emim]Ac in scCO2 with co-solvents, including ethanol, acetone and DMSO were determined respectively at 40 °C, 50 °C, 60 °C and pressure up to 15.0 MPa. The results showed that the addition of co-solvents had a significant effect on solubility of ILs in scCO2. The ability of different co-solvents to enhance solubility of [Emim]Ac in scCO2 followed the order: ethanol > DMSO > acetone. Solubility of [Emim]Ac in scCO2/ethanol or acetone decreased slowly as temperature increased. As for DMSO, temperature lower than 50 °C wouldn't be a remarkable parameter for solubility. However, observable decrease of solubility was caused by temperature higher than 60 °C. Moreover, solubility of ILs increased as pressure increased from 8 to 15 MPa. Three models were used to correlate the 216 solubility data, Modified-Christal equation possessed highest accuracy. [Display omitted] •Solubility of ILs [Bmim][NTf2] and [Emim]Ac in scCO2/co-solvent was determined.•The effect of co-solvent, temperature and pressure was investigated.•Three models were used to correlate the 216 solubility data.•Modified-Christal equation possessed highest accuracy, AARD = 1.77%–5.54%.