SO2 removal from simulated flue gas using various aqueous solutions: Absorption equilibria and operational data in a packed column

• SO2-aqueous solution equilibrium data of various absorbents was measured in a stirred batch reactor.
• Amino acid salt aqueous solutions and especially sodium lysinate had higher SO2 solubility.
• SO2 removal efficiency of absorbents was evaluated in a packed column.
• Effect of operating parameters on SO2 removal efficiency of sodium lysinate was investigated.

In this study, SO2 absorption performance of the novel amino acid salt aqueous solutions such as sodium lysinate and sodium glycinate from simulated flue gas were studied and compared with frequently utilized absorbents including ethylenediamine, 2-amino2-methyl1-propanol (AMP) and disodium hydrogen phosphate. SO2-aqueous solution equilibrium data of these absorbents at concentration of 0.1 M in a stirred batch reactor exhibited that amino acid salt aqueous solutions and especially sodium lysinate had higher SO2 solubility at 298 K. In order to ensure the SO2 removal efficiency at practical condition, the suggested absorbents were applied in a packed column. The experimental results imply better removal efficiency of amino acid salt solutions consistent with absorption equilibrium data. The effects of parameters such as temperature, SO2 inlet concentration and liquid–gas flow ratio on removal efficiency were investigated for 1 M concentration of sodium lysinate solution. SO2 removal efficiency enhanced with increasing gas–liquid flow ratio, but both temperature and SO2 inlet concentration had opposite effects.