Solubility and thermodynamic properties of SO2 in three low volatile urea derivatives

The solubilities of SO2 in three dipolar aprotic urea diversities, 1,1,3,3-tetramethylurea (TMU), 1,3-dimethyl-2-imidazolidinone (DMI), and 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H)-pyrimidinone (DMPU) was measured at temperatures ranging from (293.15 to 323.15) K and pressure up to 120 kPa. By correlating the solubility results with a reaction equilibrium thermodynamic model (RETM), Henry's constants (H-m), reaction equilibrium constants (K degrees), and enthalpy (Delta H-r) in the absorption process were obtained. The results indicate that the three solvents exhibit both strong physical and weak chemical interactions with SO2. Further comparison of the capture performance with ILs, deep eutectic solvents (DESs), and several organic solvents, DMI, DMPU and TMU are noted to be excellent absorbents for acidic SO2. (C) 2016 Elsevier Ltd.