Absorption of CO2 in aqueous mixtures of N-methyldiethanolamine and guanidinium tris(pentafluoroethyl)trifluorophosphate ionic liquid at high-pressure

In this paper, the solubility of CO2 in aqueous blends of N-methyldiethanolamine (MDEA) and guanidium tris(pentafluoroethyl)trifluorophosphate [gua]+[FAP]− ionic liquid was measured at 313.15, 333.15 and 353.15 K and at partial pressures up to 3 MPa. Reported data were loading capacity (mol CO2/total mol) as a function of CO2 partial pressure at equivalent temperature. A simple correlation was used to predict the solubility of CO2 in the mixtures. The predicted data showed good agreement with the experimental data. In this study, it has been found that adding [gua]+[FAP]− into the aqueous MDEA has lowered the absorption capacity and this effect was significant at higher concentrations.

► CO2 absorption in aqueous blend of MDEA and ionic liquids. ► Temperature range of 313.15–353.15 K and pressure range up to 3 MPa. ► Temperature and pressure effect conform to the general trend of absorption. ► Increasing ionic liquids has decreased CO2 loading capacity. ► Existence of 2 layers CO2-rich solvent.