Absorption of Sulfur Dioxide by Tetraglyme⁻Sodium Salt Ionic Liquid.

A series of tetraglyme⁻sodium salt ionic liquids have been prepared and found to be promising solvents to absorb SO₂. The experiments here show that [Na⁻tetraglyme][SCN] ionic liquid has excellent thermal stability and a 30% increase in SO₂ absorption capacity compared to other sodium salt ionic liquids and the previously studied lithium salt ionic liquids in terms of molar absorption capacity. The interaction between SO₂ and the ionic liquid was concluded to be physical absorption by IR and NMR.