Simultaneous solubility of CO2+H2S mixture into aqueous Diisopropanolamine solutions blended with 1-butyl-3-methylimidazolium acetate ionic liquid at high pressures

At this work simultaneous solubility of a gas mixture containing 70 mol% CO2 and 30 mol% H2S into aqueous solution of diisopropanolamine (DIPA) blended with 1-butyl-3-methylimidazolium acetate [bmim][acetate] ionic liquid is measured using a static high pressure equilibrium cell. The weight percent of alkanolamine and ionic liquid aqueous solution were 30, 50 wt% and 5, 10, 50 wt%, respectively. The experiments have been carried out at 323.15 and 348.15 K and in total pressure range of about 2-25 bar. The solubility data are presented in acid gas partial pressures against its molality. The results illustrate that increase in temperature and decrease in DIPA concentration lead to lower solubility of both acid gases. Also it can be deduced from the results that addition of ionic liquid at low concentrations leads to lower solubility of CO2 because it diminish the solution alkalinity. But at high concentrations, ionic liquid can cause to more solubility of CO2 through physical reactions. In case of H2S, augmentation of ionic liquid in each concentration results in higher solubility, because of high selectivity of the ionic liquid toward H2S that may lead to more physical interaction