Solubility properties and spectral characterization of sulfur dioxide in ethylene glycol derivatives

Abstract

Solubilities of SO 2 in ethylene glycol derivatives were determined by dynamic isothermal gas-liquid equilibrium (GLE) experiments, and the thermodynamic parameters of the absorption processes were calculated. The GLE results indicated that the solubilities of SO 2 in ethylene glycol derivatives increase in the order: diols < monomethyl ethers < dimethyl ethers, with the enthalpy values ranging from À23.2 to À43.3 kJ mol À1 . The regeneration experiment found that the absorption of SO 2 in tetraethylene glycol dimethyl ether is reversible, and the solvents can be reused without a significant loss of absorption capacity. The interactions between SO 2 and ethylene glycol derivatives were investigated by UV, IR and NMR. In addition, a 1 H-NMR spectroscopy technique with external references was used to investigate the physical absorption process of SO 2 for the first time, in order to avoid the influence of deuterated solvents. Spectroscopic investigations showed that the interactions between SO 2 and ethylene glycol derivatives are based on both the charge-transfer interaction and hydrogen bond. Ethylene glycol derivatives with desirable absorption capacities and excellent regeneration abilities are promising alternatives to conventional sorbents in SO 2 separation.

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

“…The promising alternative EG and its derivatives had become the subject of the increasing interests in FGD processes, because of their favorable absorption and regeneration properties for SO 2 [11][12][13][14][15][16]. In the recent work, we discovered that the SO 2 solubility in DMSO was stronger than in EG, which agreed well with literature [17], and DMSO also showed a remarkable regeneration properties for SO 2 .…”

“…Another factor was the O ! S chargetransfer interaction of hydroxyl oxygen atoms in EG with sulfur atom in DMSO resulted in forming greater conjugation system in DMSO molecule, and leading red-shift of corresponding absorption wavelength [14]. The present results showed that the intermolecular hydrogen bonding and O !…”

“…Otherwise, the higher conjugation degree in SO 2 molecule from possible O ! S charge-transfer interactions could also lead to red-shift of the corresponding absorption wavelength [14]. For n !…”

“…external references [14]. Samples and CDCl 3 were injected into capillary tubes (25 cm  0.9 mm) and NMR tubes (17.8 cm  5 mm), respectively.…”

Solubility and thermodynamic properties of SO 2 in three low volatile urea derivatives

“…Many traditional solvents such as DMF [16], DMSO [16], DMA [16], SUF [16,17], TBP [16], DEA [16], PC [17], NMP [17][18][19][20], and ethylene glycol [17] as well as its derivatives [21] or mixtures [22] have been reported in SO 2 removal. In addition, N-substituted imidazoles [17,23,24] are also confirmed as SO 2 capturer with superior performance.…”