In this work, an air-blast atomizing column was used to study the CO₂ capture performance with aqueous MEA (mono-ethanol-amine) and NaOH solutions. The effects of gas flow rate, the liquid to gas ratio (L/G), the CO₂ concentration on the CO₂ removal efficiency (η) and the volumetric overall mass transfer coefficient (KGav) were investigated. The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO₂ capture performance. For the aqueous MEA and NaOH solutions, the experimental results show that the ηdecreases with increasing gas flow rate and CO₂ concentration while it increases with increasing L/G. The effects on K_Ga_v are more complicated than those for η. When the CO₂ concentration is low (3 v/v%), K_Ga_v increases with increasing gas flow rate while decreases with increasing L/G. However, when the CO₂ concentration is high (9.5 v/v%), as the gas flow rate and L/G increases, K_Ga_v increases first and then decreases. The aqueous MEA solution achieves higher η and K_Ga_v than the aqueous NaOH solution. The air-blast atomizing column shows a good performance on CO₂ capture.

In this work, an aqueous (2-hydroxyethyl)-trimethyl-ammonium (S)-2-pyrrolidinecarboxylic acid salt ([Cho][Pro]) + K2CO3 solution was studied as a novel absorbent for CO2 capture, and the kinetics and mechanism of the CO2 absorption/desorption process were systematically investigated. Adding [Cho][Pro] to the aqueous K2CO3 solution improved the absorption rate of the solution during the initial stage, and the apparent CO2 absorption rate increased as the concentration of [Cho][Pro] increased. Meanwhile, equilibrium was reached faster when [Cho][Pro] was added, and a tradeoff was noticed between the apparent absorption rate constant and equilibrium absorption amount. The desorption rates of the CO2-rich aqueous [Cho][Pro] + K2CO3 solutions were higher than that of the aqueous [Cho][Pro] solution at 363.15 K, and the highest apparent desorption rate constant was achieved for the aqueous 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 solution. A further study on the aqueous 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 solution indicated that the desorption amount increased with the increase in the temperature from 348.15 to 365.15 K. Moreover, with further increase in temperature, the desorption amount exhibited a lower increasing rate when temperature was higher than 361.15 K. The 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 absorbent exhibited more stable regeneration performance after 7 cycles and lower desorption activation energy than the aqueous 30 wt.% monoethanolamine (MEA) and 30 wt.% [Cho][Pro] solutions as well as higher working capacity compared to the aqueous 30 wt.% [Cho][Pro] solution.

Supported ionic liquid (IL) sorbents for CO₂ capture were prepared by impregnating tetramethylammonium glycinate ([N₁₁₁₁][Gly]) into four types of porous materials in this study. The CO₂ adsorption behavior was investigated in a thermogravimetric analyzer (TGA). Among them, poly(methyl methacrylate) (PMMA)-[N₁₁₁₁][Gly] exhibits the best CO₂ adsorption properties in terms of adsorption capacity and rate. The CO₂ adsorption capacity reaches up to 2.14 mmol·g^{− 1} sorbent at 35 °C. The fast CO₂ adsorption rate of PMMA-[N₁₁₁₁][Gly] allows 60 min of adsorption equilibrium time at 35 °C and much shorter time of 4 min is achieved at 75 °C. Further, Avrami's fractional-order kinetic model was used and fitted well with the experiment data, which shows good consistency between experimental results and theoretical model. In addition, PMMA-[N₁₁₁₁][Gly] remained excellent durability in the continuous adsorption–desorption cycling test. Therefore, this stable PMMA-[N₁₁₁₁][Gly] sorbent has great potential to be used for fast CO₂ adsorption from flue-gas.