A comparative study for CO2 absorption among amino acids (AAs) and ionic liquids (ILs) containing tetramethylammonium [TMA] and tetrabutylphosphonium [TBP] as cations and the corresponding deprotonated amino acid as anions, namely, [TMA][AA] and [TBP][AA], is reported. Amino acids show an excellent performance for CO2 capture, better than the corresponding [TMA][AA], but AAs are less efficient than [TBP][AA]. In addition, [TBP][AA] present faster kinetics of absorption than the corresponding AA. [TBP][lysinate] exhibits the highest CO2 absorption capacity. A novel and fast method with low energy demand for microwave-assisted regeneration of the absorbents from the CO2-saturated solution is also described for the first time.