Spectral Investigation of Intermolecular Hydrogen Bonding and S...−O Interaction in Diethylene Glycol + H₂O + SO₂Systems

Abstract

Diethylene glycol (DEG) + H2O solutions (DEGWs) were used as the promising medium for the absorption processes of SO2. In this work, when UV, FTIR,1H NMR, and fluorescence spectroscopic techniques were used for inspection of spectral changes of DEGWs with increasing SO2 concentration, the results suggest that H2O can interact with DEG by hydrogen bonds as the formation of −CH2CH2O(H)...−HOH...− and −CH2−CH2−O(CH2−CH2−)...−HOH...− in DEGWs. Furthermore, SO2 can interact with DEG in various DEGWs by hydrogen bonds as the formation of −CH2CH2OH...−OSO...− and the intermolecular S...−O interaction in the absorption processes of SO2, which was not discussed in the previous similar systems. The results of this work can be used to provide an important absorption mechanism for the design and operation of the absorption and desorption process in flue gas desulfurization with potential industrial application of DEG aqueous solutions.