Solubilities of CO2 in some glycol ethers under high pressure by experimental determination and correlation

The binary vapor–liquid equilibrium data of CO2 in diethylene glycol (monomethyl, monoethyl, monobutyl, dimethyl, diethyl, dibutyl) ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method. It was found by contrast that the ether group in solvents can promote the CO2 absorption, but the hydroxyl group will inhibit the CO2 absorption. Furthermore, the solubilities of CO2 showed an upward trend with the increasing molecular lengths of absorbents. The experimental data were also correlated with a modified Patel–Teja equation of state (PT EOS) combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.

Graphical abstractThe constant-volume method is used to determine the solubility of CO2 in diethylene glycol (monomethyl, monoethyl, monobutyl, dimethyl, diethyl, dibutyl) ether under the pressure of 6 MPa and the temperature variations from 288.15 to 318.15 K in this paper. The obtained results demonstrated that the solubilities of CO2 in the ‘diether’ solvents are better than the ‘monoether’ solvents, which suggested that the ether group in solvents can promote the CO2 absorption.Figure optionsDownload full-size imageDownload as PowerPoint slide