Experimental Investigation on the Solubility and Initial Rate of Absorption of CO₂ in Aqueous Mixtures of Methyldiethanolamine with the Ionic Liquid 1-Butyl-3-methylimidazolium Tetrafluoroborate

In this paper we present the results of the initial absorption rate and solubility of CO 2 in aqueous 4 M methyldiethanolamine (MDEA) mixed with various concentrations of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF 4 ]) at (303, 313, 323, and 333) K. All experiments were carried out at low partial pressures of CO 2, below 110 kPa. The results of this research suggested that the presence of a low concentration of [bmim][BF 4 ] in aqueous 4 mol·L −1 MDEA has no significant effect on the mixture loading capacity, but increased the initial absorption rate. The amine CO 2 loading capacity showed a significant decrease in the presence of high concentrations of ionic liquid in the mixture.