Gas−Liquid Equilibrium Data for Sulfur Dioxide + Nitrogen in Diethylene Glycol + Water at 298.15 K and 123.15 kPa

Abstract

Isothermal gas−liquid equilibrium (GLE) data have been measured for the system diethylene glycol (DEG) (1) + water (2) + SO2 (3) + N2 (4) at 298.15 K and 123.15 kPa and SO2 partial pressures in the range of (0.7 to 100) Pa. Measurements were carried out by a saturation method using a glass absorption apparatus, which was controlled at constant temperatures by a thermostatic circulation bath with a Beckmann thermometer. The GLE compositions were obtained with relative uncertainties within ± 0.6 % for SO2 concentration in the liquid phase and ± 3.5 % for SO2 mole fraction in the gas phase. The measurement showed that the system DEG (1) + water (2) in the mass fraction range of w1 = (0.60 to 1.00) decreased the solubility of SO2 and the system DEG (1) + water (2) in the mass fraction range of w1 = (0.00 to 0.60) increased the solubility of SO2. Compared with our previous work (Zhang, J. B.; Wei, X. H.; et al. J. Chem. Eng. Data 2008, 53, 2372−2374; Zhang, J. B.; Wei, X. H.; et al. J. Chem. Eng. Data 2009, DOI: 10.021/je900392e), the solubility of SO2 in pure DEG is 259 mg·L−1 when SO2 volume fraction in the gas phase is Φ3 = 5·10−4, which is higher than in pure ethylene glycol (EG, 128 mg·L−1) and lower than in pure poly(ethylene glycol) 400 (PEG 400, 1330 mg·L−1). The results of this work can be used to provide important GLE data for the design and operation of the absorption and desorption process in flue gas desulfurization (FGD) with potential industrial application of various PEG aqueous solutions.