Absorption, desorption and spectroscopic investigation of sulfur dioxide in the binary system ethylene glycol + dimethyl sulfoxide

Isothermal gas–liquid equilibrium (GLE) data were measured at 298.15   K and 122.66   kPa for dilute SO 2 in the binary system ethylene glycol (EG)   +   dimethyl sulfoxide (DMSO), in which SO 2 partial pressures were calculated in range of (0–130)   Pa. The solubility of dilute SO 2 in the binary system gradually increased with the increasing DMSO concentration in the whole composition . Based on the GLE data, Henry’s law constants ( HLC ) of dilute SO 2 in the binary system EG (1)   +   DMSO (2) were obtained. The regeneration experiments showed that the 97.6% SO 2 could be separated from the dissolving SO 2 solution at 80   °C and bubbling N 2 within 30   min; meanwhile, SO 2 desorption ran smoothly and solubility of SO 2 no significant dropped after five-successive absorption–desorption cycles. Furthermore, to obtain important reaction mechanism, the intermolecular interaction among SO 2 , EG, and DMSO were investigated by UV–vis, FTIR, and 1 H NMR spectroscopic techniques. Spectral results showed that the interaction among EG, DMSO, and SO 2 were resulted from both the O   →   S charge-transfer interaction and intermolecular hydrogen bonding .