Kinetics of Carbon Dioxide Absorption into Mixed Aqueous Solutions of MEA + [Bmim]BF4 Using a Double Stirred Cell

An aqueous blend of monoethanolamine (MEA) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF 4 ) for CO 2 absorption from simulated flue gas was investigated using a double stirred cell at a CO 2 partial pressure of 15 kPa. It was found that the values of the enhancement factor ( E ) and the second-order reaction rate constant ( k 2,mix ) for CO 2 absorption into mixed solution were higher than those into a single MEA aqueous solution with the same MEA concentration. k 2,mix and k 2, IL were found to be 3487.6 m 3 ·kmol –1 ·s –1 and 1936.7 m 3 ·kmol –1 ·s –1 at 303.15 K, respectively. The Arrhenius equation of CO 2 absorption was also estimated. The results proved the assumption that [Bmim]BF 4 had an active effect on the CO 2 hydration. The diffusion and solubility of the absorbent in the solution were the limiting factors of the reaction.