Absorption Of CO₂in The Aqueous Solutions Of Functionalized Amino Acids Ionic Liquids [N₁₁₁₁][Gly]

CO₂separation and capture has been extensively studied in recent years due toits environmental concern of global warming and potential C1resources. Features ofan advanced aqueous amine solvent of tetramethylammonium glycinate ([N₁₁₁₁][Gly])and mixed solutions systems, absorption mechanism, kinetics region and regenerationbehavior were studied, which may serve as a groundwork for future study.Density, viscosity and pH of the single [N₁₁₁₁][Gly] solutions, withconcentrations ranging from5%to30%, were determined at temperatures from298to323K. Solubility and diffusivity of CO₂in [N₁₁₁₁][Gly] solution at the sametemperatures and concentrations were estimated. The result showed that density,viscosity and pH of [N₁₁₁₁][Gly] aqueous solutions increased as the mass fraction ofthe [N₁₁₁₁][Gly] increased and decreased as the temperature increased, and thesolubility of CO₂and diffusion coefficient of CO₂in the [N₁₁₁₁][Gly] aqueoussolution decreased systematically as the mass fraction of [N₁₁₁₁][Gly] increased, butshowed the opposite phenomenon with the increase of temperature. Absorption ofCO₂into [N₁₁₁₁][Gly] aqueous solution was investigated using a double stirred-cellabsorber with a planar gas-liquid interface. The effects of the [N₁₁₁₁][Gly]concentration, temperature and CO₂concentration of absorption CO₂into aqueous[N₁₁₁₁][Gly] were studied. It showed that both the CO₂absorption rate and theabsorption amount increased as the increase of the [N₁₁₁₁][Gly] concentration,temperature and the CO₂concentration. The kinetics study showed that absorptionCO₂into aqueous [N₁₁₁₁][Gly] was the fast pseudo-first order reaction regime, E waslinear with CB01/2, and the activation energy of15%aqueous [N₁₁₁₁][Gly] absorbingCO₂was15.431kJ mol-1. To determine its regeneration behavior, single aqueous[N₁₁₁₁][Gly] was investigated by the means of heating under diminished pressure orstandard atmosphere. The result showed that the mean of heating under diminishedpressure seemed more favorable for the regeneration of saturated [N₁₁₁₁][Gly]solutions. The most suitable regeneration temperature and time for [N₁₁₁₁][Gly] aqueous solution are348K and4h respectively, and the first, second and thirdregeneration efficiency were92.99%,88.89%and82.46%, respectively.On the basis of the above study, the density, viscosity and pH of [N₁₁₁₁][Gly]solutions added to0.95mol/L AMP aqueous solution were investigated with additiveconcentrations of0⁰.40mol/L, at a temperature range of298³23K. Solubility anddiffusivity of CO₂in [N₁₁₁₁][Gly]+AMP solutions at the same temperatures andconcentrations was estimated. The result showed that density and viscosity of[N₁₁₁₁][Gly]+AMP aqueous solutions increased as the [N₁₁₁₁][Gly] concentrationincreased and decreased as the temperature increased, and the solubility of CO₂anddiffusion coefficient of CO₂in the [N₁₁₁₁][Gly] aqueous solution decreased as the[N₁₁₁₁][Gly] concentration increased, but showed the opposite phenomenon withincreasing temperature.The reaction kinetics of CO₂into [N₁₁₁₁][Gly]+AMP aqueoussolution was investigated. The results indicated that [N₁₁₁₁][Gly] could greatlypromote the absorption and increase the absorption rate of CO₂in0.95mol/L AMPaqueous solutions, but there was a weak negative interaction in the system of thehigher reaction rate of [N₁₁₁₁][Gly] with the higher equilibrium capacity of AMP. Thekinetics region of absorption CO₂into aqueous [N₁₁₁₁][Gly]+AMP was the fastpseudo-first order reaction regime. Moreover, the enhancement factor E was linearwith CB01/2and△E linear with CAMP, and the activation energy of [N₁₁₁₁][Gly]+AMPaqueous solution absorbing CO₂was40.6779kJ mol-1. The regeneration resultshowed that the mean of heating under diminished pressure seemed more suitable forregeneration saturated [N₁₁₁₁][Gly]+AMP solutions. The optimal regenerationtemperature and time for [N₁₁₁₁][Gly]+AMP aqueous solution are328K and4hrespectively, and the first, second and third regeneration efficiency of[N₁₁₁₁][Gly]+AMP aqueous solution were93.23%,90.00%and87.31%, respectively.