High-pressure CO2 solubility measurement in aqueous mixtures of (2-amino-2-methyl-1-propanol (AMP) and deep eutectic solvent (tetra butyl ammonium bromide 1: 3 ethylene glycol)) at various temperatures

In this work, we measured the CO2 solubility in a mixture of aqueous 2-amino-2-methyl-1-propanol (AMP) and deep eutectic solvent (DES) made by tetra butyl ammonium bromide (TBAB) and ethylene glycol (EG) statically at high-pressure. Measurements were performed isothermally at 313.15, 328.15, and 343.15 K and in the pressure range of 100-5100 kPa. The solvent compositions used for the DES (TBAB 1: 3 EG) + AMP + H2O systems were (7.5-30-62.5) (15-30-55) (22.5-30-47.5) and (30-30-40) wt.%. The solubility results showed that decreasing temperature and increasing pressure enhanced the solubility of CO2 in the solvent mixtures. Also, increasing the mass concentration of deep eutectic solvent in the system at a constant temperature reduces the gas's solubility. Besides, in this study, a correlation of gas partial pressure against CO2 loading and temperature was obtained to calculate the gas solubility in the studied system, which agrees with the experiment. Finally, the heat absorption enthalpy of CO2 was calculated using the Clausius-Clapeyron equation. The enthalpy of disso-lution changed with a smoother slope as the mass percentage of DES increased.