Double bond carboxylate ionic liquids for reversible SO2 capture

Solubility of SO2 in [N-2224][Met] was measured at temperature from 313.2 to 333.2 K and pressure up to 1.8 bar. The [N-2224][Met] absorbed SO2 at high speed and could be recycled for four times. The Reaction Equilibrium Thermodynamic Model (RETM) was used to correlate the experimental data, Henry's constant (H), reaction equilibrium constant (K-0), and thermodynamic properties (Delta H-r(m)0, Delta(r)G(m)(0), Delta S-r(m)0, Delta H-phy and Delta H-chem) were derived. Considering the absorption capacity and low absorption enthalpy, as well as the fast absorption process, [N-2224][Met] is thought to be a promising absorbent to ordinary solvent as a desulfurizer.