Phase equilibria of high pressure CO2 and deep eutectic solvents formed by quaternary ammonium salts and phenol

• Published in: Fluid phase equilibria Vol. 429; pp. 14 - 20
• Main Authors: Ji, Youan, Hou, Yucui, Ren, Shuhang, Yao, Congfei, Wu, Weize
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2016
• Subjects: Carbon dioxide; Chlorides; Deep eutectic solvent; Eutectics; High pressure CO2; Phase equilibria; Phenol; Quaternary ammonium salt; Quaternary ammonium salts; Solubility; Solvents; Phase equilibria; Quaternary ammonium salt; High pressure CO2; Phenol; Deep eutectic solvent
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2016.08.020

Phase equilibria of the binary systems of high pressure CO2 + deep eutectic solvents (DESs) formed by quaternary ammonium salts (QASs, including 2-hydroxy-N, N, N-trimethyl-ethanaminium chloride, ChCl; N, N, N-trimethyl-methanaminium chloride, TMAC; and N, N, N-triethyl-ethanaminium chloride, TEAC) and phenol were measured at temperatures from 313.15 K to 333.15 K, pressures from 1.71 MPa to 13.3 MPa and mole ratios of phenol to QAS from 2.00 to 4.00. It has been found that two-phase equilibrium exists at all the studied conditions. The solubility of phenol in the CO2 phase and the solubility of CO2 in the DES phase at different pressures, temperatures, mole ratios of phenol to QAS have been obtained. Both the solubility of phenol in the CO2 phase and the solubility of CO2 in the DES phase formed by ChCl and phenol shows the largest, while those in the DES phase formed by TEAC and phenol shows the smallest. This work provides phase equilibrium data for phenol extraction and QAS regeneration. [Display omitted] •Phase equilibria of high pressure CO2+deep eutectic solvents (DESs) were measured.•DESs were formed by phenol and 3 quaternary ammonium salts with 2–4 mol ratios.•Two-phase equilibrium were observed at 313.15–333.15 K and 1.71–13.3 MPa.•CO2 could dissovled in the DES phase and only phenol dissovled in the CO2 phase.