Characterization and absorption of carbon dioxide into aqueous solution of amino acid ionic liquid [N1111][Gly] and 2-amino-2-methyl-1-propanol

Abstract

Amino acid ionic liquid tetramethylammonium glycinate ([N1111][Gly]) was mixed with 2-amino-2-methyl-1-propanol (AMP) aqueous solution to form a new solvent for CO2 capture. The density, viscosity and pH of 0–0.40molL−1 [N1111][Gly]+0.95molL−1 AMP aqueous solution were investigated at a temperature range of 298–323K. Solubility and diffusivity of CO2 in [N1111][Gly]+AMP solutions at the same temperatures and concentrations was estimated. The reaction kinetics of CO2 absorption into [N1111][Gly]+AMP aqueous solution was investigated using a double stirred-cell absorber with a planar gas–liquid interface. The results indicated that [N1111][Gly] promoted the absorption of CO2 in 0.95molL−1 AMP aqueous solutions. The kinetics region of absorption CO2 into aqueous [N1111][Gly]+AMP solution was the fast pseudo-first order reaction regime. Moreover, the enhancement factor E was linear with CB01/2 and ΔE linear with the concentration of [N1111][Gly] in the mixed aqueous solution, and the activation energy of [N1111][Gly]+AMP aqueous solution absorbing CO2 was 40.7kJmol−1.