Solubility and density of carbon dioxide in different aqueous alkanolamine solutions blended with 1-butyl-3-methylimidazolium acetate ionic liquid at high pressure

Abstract

Using a static high pressure equilibrium cell, the new set of the experimental data is obtained for solubility of carbon dioxide in the aqueous mixtures of different type of alkanolamines such as N-methyldiethanolamine (MDEA), Diethanolamine (DEA), Diisopropanolamine (DIPA), 2-amino-2-methyl-1-propanol (AMP), and 1-butyl-3-methylimidazolium acetate ionic liquid [bmim] [acetate]. The solubility of CO2 in the aqueous MDEA+[bmim][acetate], DEA+[bmim][acetate], DIPA+[bmim][acetate] and AMP+[bmim][acetate] solutions with 0–10wt% of ionic liquid and 30–40wt% alkanolamine are carried out at 1 to 40bar and 323.15K. Moreover, the temperature dependency of density for these solutions is measured from 293.15 to 343.15K with 10K intervals.The results of the CO2 solubility are represented by partial pressure of CO2 against the loading and mole fraction of CO2. The solubility of the CO2 in all of the aqueous alkanolamine+ionic liquid solutions decreases with increasing weight percent of ionic liquid. Also, the results show that the maximum decrease of CO2 loading belongs to addition of [bmim] [acetate] to the aqueous MDEA solution. Finally, the results of density of the alkanolamine+ionic liquid solutions present that the density enhances with increasing concentration of [bmim][acetate] and reduces linearly with enhancing temperature.