Solubilities and thermodynamic properties of SO2 in five biobased solvents

Five biobased solvents (BBSs) with high boil point, namely ethyl levulinate (EL), butyl levulinate (BL), dibutyl succinate (DBS), gamma-butyrolactone (GBL) and gamma-valerolactone (GVL), were applied in absorption of SO 2 . The solubilities of SO 2 in the BBSs were determined at temperatures (293.15 to 333.15)   K and pressures (0 to 120)   kPa. Henry’s constant and thermodynamic properties (standard dissolution Gibbs energy, dissolution enthalpy, dissolution entropy) were further calculated according to the solubility data. The gravimetric solubilities in BBSs changed with the sequence of GBL   >   GVL   >   EL   >   BL   >   DBS. The solubility of SO 2 and absorption enthalpy in present BBSs and other molecular solvents as well as ionic liquids (ILs) were systemically compared. The results illustrated that GBL and GVL possessed the potentiality to capture SO 2 among all absorbents due to their relatively large solubility and low absorption enthalpy for SO 2 , biodegradability, low toxicity, inexpensive cost and low viscosity.