Journal of Chemical and Engineering Data, Vol.52, No.2, 596-599, 2007
Hydroxyl ammonium ionic liquids: Synthesis, properties, and solubility of SO2
To explore environmentally benign solvents for absorbing SO2, a series of hydroxyl ammonium ionic liquids (ILs) was synthesized and characterized, and the solubilities of SO2 in these synthesized ILs were determined. It was found that the solubilities of SO2 in these ILs at ambient pressure are quite high, for example, the solubility of SO2 in tri-(2-hydroxyethyl)ammonium lactate is 0.4957 mole fraction and decreases sharply as temperature increase. The absorption and desorption are practically reversible in the synthesized ILs. Comparing with the conventional absorbents such as calcium carbonate (CaCO3), calcium oxide (CaO), and sodium hydroxide (NaOH), the synthesized ILs show two advantages: one is that the ILs can be recycled and repeatedly used, another is that the absorbed SO2 can be reversibly released and recovered as a sulfur resource.