Equilibrium solubility measurement of carbon dioxide in hybrid solvents of aqueous N-methyldiethanolamine blended with 1-Methyl-3-octyl-imidazolium tetrafluoroborate ionic liquid at high pressures

[Display omitted] •Solubility of CO2 in aqueous solution of MDEA and ionic liquids is measured.•The ionic liquid 1-methyl-3-octyl-imidazolium tetrafluoroborate were studied.•The solubility of CO2 is reduced with increasing the amount of ionic liquid.•The solubility of Carbon dioxide is decreased with increasing the temperature.•The experimental data are correlated with a semi empirical model with good accuracy. Solubility of CO2 in the hybrid solvents composed of aqueous N-methyldiethanolamine (MDEA) blended with 1-methyl-3-octyl-imidazolium tetrafluoroborate ([Omim][BF4]) ionic liquid (IL) was measured at temperatures from (298.15–343.15 K) and pressures of (0.2–4 MPa). The experimental trials were performed in a static high pressure equilibrium cell to determine the CO2 absorption capacity of novel absorbent solutions based on the isochoric saturation technique. The experimental data showed that, by rising the concentration of IL in the absorbent solutions’, the mole fraction of dissolved CO2 gas enhances gradually. Absorption capacity of these aqueous solutions was assessed and compared with pure ILs and alkanolamine solvents, which indicates the solutions studied in this research as better hybrid solvents in terms of CO2 loading. Furthermore, a semi empirical model is used to correlate the solubility data of this work, which presents a good agreement with an absolute average deviation (AAD %) of below 1%.