Solubility of sulfur dioxide in tetraglyme-NH(4)SCN ionic liquid: high absorption efficiency

An easily prepared ionic liquid was synthesized by a one-step method and applied in SO(2) absorption efficiently. The cation of the ionic liquid is a supramolecular structure consisting of NH(+)(4) and tetraglyme, similar to the structure of NH(+)(4) and crown ether, and the anion is selected as SCN(−). The ionic liquid has good thermal stability. Under the conditions of 293 K and 1 bar, one mol ionic liquid can absorb 2.73 mol SO(2), which is about 30% higher than tetraglyme. The absorption mechanism was characterized using IR and NMR. And the results confirmed that the interaction mechanism between SO(2) and the ionic liquid is a physical interaction rather than a chemical interaction.